Overall, I found the services fun and easy to use. There is no limit to how many personalized voice mails you can record, so everyone on your contact list can hear a greeting just for them. It’s labor-intensive to set up, but online forms are easy to navigate. The services make money by selling ads on their sites.

In addition to tailored greetings, YouMail lets you save your voice-mail messages, email your saved messages via audio files, share messages using a URL link, retrieve deleted messages, and see who called you and when and whether they listened to your message. You can do all this online, or from your phone — if it has Internet service.

You check your voice mail by phone or over the Internet. As with your carrier’s voice-mail service, you can simply dial an access number and listen to messages. I logged into my account at youmail.com and clicked on “My Voicemail.” The sound quality was superb, as it was when I listened to the audio files that were sent to my Yahoo inbox. (I gave my email address when I signed up.)

I also checked messages from other phones by dialing the access number. The service doesn’t interfere with voice mails already saved on your regular carrier’s system.

YouMail gives you the option of keeping your voice mails indefinitely. Messages are stored in your online account and offer you an email audio file as backup.

One fun feature in YouMail is DitchMail, which blocks messages from certain callers. They don’t even get a chance to leave a message. You ditch a caller by double-clicking on their names in your online phonebook and checking the DitchMail option, or by pressing 86 on your phone after hearing a message from a person you don’t want to hear from again. When dumpees call your number, they’ll hear either a standard message — “This number has been disconnected” — or one you record.

Users can record special greetings or upload ones online if their computers have microphones; otherwise, they just press 0 on their phone keypad to record.

Signing up on YouMail.com is simple. You just register your mobile number and email address, and receive a confirmation code via text message on your cellphone. Switching from your main carrier’s voice mail to YouMail takes a few minutes and switching back is just as simple. Instructions are available on the site.

YouMail has its drawbacks. The access number you use to retrieve messages is long distance, so it can get costly with some plans. And depending on your text-messaging plan, you’ll likely be charged for the alerts you get whenever someone leaves a message. But you can turn off the text-message option.

GrandCentral is even easier to use when it comes to recording multiple greetings and dumping unwanted callers. One caveat: GrandCentral is in a beta, or testing, phase. You must be invited by a member to sign up.

The service gives users another phone number, based on their ZIP Code, to which they can link their cellphone, office and home numbers. You can hand out GrandCentral’s one unified number and check just one mailbox.

I like GrandCentral’s Web interface better than You Mail’s. The features are very simple to use. You start by adding contact numbers online and recording greetings for individuals. When people call your unified number, all the phones you linked ring so you can pick up any of them. When you answer, you hear a recorded message telling who is calling and giving you options of how to handle that call. Meanwhile, the caller hears only the phone ringing.

The service recognizes each caller in your address book; new callers have to say their names the first time they call, and from then on, the service recognizes them, too.

I like the feature that lets you screen calls. When someone calls your GrandCentral number, your phone displays Caller ID information. When you pick up, a recorded message states the caller’s name and offers fours ways to handle the call: 1 to answer, 2 to send the caller to voice mail, 3 to listen in while a message is being recorded, or 4 to accept and record the call. If you press 3 and then decide you want to answer a call, you can press the star key to pick up.

Blocking a caller is similar to that YouMail feature. The callers can’t leave a message, and they hear a prerecorded message that your number is no longer in service. But unlike with YouMail, your phone won’t ring and you can’t leave the blocked caller a customized message.

Both services spice up your voice mail. And considering they’re free, they’re worth a try.

Walt Mossberg is on vacation. Find all of his columns and videos online free at the new All Things Digital Web site, http://walt.allthingsd.com.

Email me at Sarmad.Ali@wsj.com.

A slew of new services using voice-recognition technology aim to eliminate the hassle of checking voice messages on wireless devices. These services transcribe recorded messages into text, which then is sent as email to email-equipped devices such as personal digital assistants and BlackBerrys, or as a short text message to phones that don’t have the email function. If in doubt about transcripts’ accuracy, you can always click on the attached audio files or dial in to hear the original voice mail.

To see how efficient these services are at transcription, I tested two voice-recognition applications: one from start-up SimulScribe, based in New York, and another from Atlanta-based SpinVox, a subsidiary of SpinVox Ltd. of the U.K.

Overall, both services work pretty well and are easy to use. I was able to read transcribed texts in a fraction of the time I would have spent dialing in to hear them. I was also able to sift through my messages and go directly to the ones I wanted to check, as opposed to having to listen to every single one sequentially. And the transcripts end the hassle of having to jot down names, numbers or addresses.

Another advantage is that the transcribed messages are sent immediately after the voice mails. When I was on a train and passing in and out of reception areas, I got my written messages faster than if I had tried voice mail only. Users can forward the messages to others or reply by calling back, sending an email or text messaging.

Signing up with SimulScribe.com took just minutes. After setting up an online account naming a cellphone carrier, I got a confirmation email with instructions on how to activate the service on my phone. SimulScribe, launched this past September, costs $9.95 a month for 40 transcribed messages plus 25 cents for each additional message. The service is compatible with all wireless carriers.

Currently, SimulScribe transcribes English voice mails only. A voice mail left on my phone in Spanish wasn’t transcribed at all. The company says it’s testing a Spanish system to add to the service in a couple of weeks.

Activating SpinVox’s Spin-my-Vmail on the phone was easy, too. After signing up on spinvox.com, the company sends subscribers a guide to using the service on the phone. I was able to activate “call forwarding busy/no answer” to divert messages to my SpinVox voice mail just by changing a setting in my T-Mobile’s cellphone settings menu.

I received an email in my mailbox whenever someone left me a voice mail. Each had the number of the caller, the transcript, date and time the message was received, plus a message code I could type into the keypad after accessing my voice mail to hear the original audio.

U.S. customers can get a free one-year trial by sending an email to gamma@spinvox.com, during which time the company expects to launch the service in the U.S. first through Cincinnati Bell and later through other carriers. Bloggers can also test Spin-my-Blog, which lets users speak a posting to their blogs from any phone. Sign-up for that is also at spinvox.com.

SpinVox, first launched in the U.K. in May 2005, transcribes in English, French, Spanish and German. Unlike SimulScribe, messages left to me in Spanish were successfully transcribed.

One friend who left me a voice mail on both services said she was pleased to be reminded by SimulScribe that her message would be transcribed so she should speak slowly and clearly.

Users of SimulScribe get unlimited inbox storage so they don’t have to delete old mail. Both services work better with hand-held email devices such as Treos or BlackBerrys than with the cellphones that don’t have the email capability. The number of characters that can be transcribed into SMS text is limited.

With SimulScribe, long messages delivered by SMS are parsed over multiple text messages. The same happens when customers use SpinVox on CDMA cellphones. Customers using SpinVox on GSM phones like those from Cingular or T-Mobile fit three-minute calls on one text.

Sometimes, the transcriptions contain misspellings, missing words or unnecessary punctuation marks. A friend left me a voice mail on my cellphone with SpinVox’s Spin-my-Vmail service. She ended it by asking me if I was sick of Thai food, but the transcribed note, amusingly, turned it into: “Hi Sarmad, it’s Kain(?). I’m calling at 4:09(?). I just wanted to see what the plans were for tonight. Are you interest in dinner, are you up for Lasagna(?).”

Words — mostly names — spelled phonetically, some numbers and undecipherable words are usually followed by a question mark.

Aside from sporadic imprecision, I liked SimulScribe more, mostly because it eliminates the need to dial in any passwords to get a voice version of transcribed messages. But it’s hard to beat the free trial of SpinVox and its multiple-language transcription capability. Both services are a nice addition to hand-held devices if you can overlook a few nuisances.

• Email me at sarmad.ali@wsj.com. Walt Mossberg is on vacation.

I attended the iPhone launch event, and was able to use one for a little while. That’s too brief an encounter to allow me to write a proper review. But I can say that it has the largest and most beautiful screen I’ve ever seen on a cellphone, even though it’s incredibly thin. It felt great in my hand. It has a brilliant new user interface; the handsomest email program and Web browser I’ve ever seen on a phone; a full-blown iPod music and video player built in; and even a cool new voicemail system.

The iPhone has some potential downsides — it doesn’t use a physical keyboard, instead relying on a virtual keyboard on the screen, which may put off heavy email users. It runs on the relatively slow EDGE cellular data network, though that flaw is partly offset by the fact that it can also use speedy Wi-Fi wireless networking. And, with a $499 base price, it’s expensive.

Still, the iPhone made my relatively new Treo 700p seem primitive in many respects when I compared them side by side. And the Apple product isn’t Palm’s only problem.

Palm’s position as the design leader in smart phones has been under assault for months. Major phone makers like Motorola and Nokia have introduced models that have most of the Treo’s capabilities but are thinner, sleeker and lighter — and much less expensive.

The Treo maker is starting to respond, but haltingly. It has brought out a couple of slightly smaller new models, but they’re no match in sleekness or style for competitors like the Motorola Q. They also aren’t as cheap. They do, though, have some advantages in software and functionality that, for some users, will make them preferable.

I’ve been testing the latest skinny contender, the Samsung BlackJack, along with Palm’s newest Treo, the slimmed-down Treo 750. Both of these phones — like the Apple phone — run on the Cingular Wireless network. Both also use Microsoft’s Windows Mobile software.

The new Treo 750 is slimmed down a bit from the familiar Treo 700 and 650 models. The 750 is also a little shorter, because it does away with the protruding antenna. In addition, it’s a hair thinner and about 16% lighter.

But next to the new Samsung BlackJack, the Treo 750 looks bulky. The BlackJack is a striking, all-black model in the slim tradition of the Motorola Q. It manages to cram a full keyboard, like the Treo’s, into a body that is much sleeker and better looking. The BlackJack is 35% lighter — and 36% smaller overall — than the Treo 750. It has a physically smaller screen, but that screen has a third better resolution than the Treo’s. (Of course, both screens look tiny and grainy compared with the display on the new Apple phone.)

Also, the BlackJack claims 38% better battery life than the Treo, and it runs on a faster data network than the Treo. (Neither phone includes Wi-Fi.) And, to top it all off, the BlackJack is half the price — $199, compared with $399 for the Treo 750.

One of the Treo’s biggest advantages has been its Palm software, which I consider to be better designed for email and phone calls than the Windows Mobile software from Microsoft. But the new 750 model can’t claim that advantage because, while it has Palm hardware, it uses the Microsoft software.

The Treo does have a small software advantage over the BlackJack. It uses a fuller version of Windows Mobile that has more features than the stripped-down version used on the BlackJack and the Motorola Q. And, because it has a touch screen, the Treo is easier to navigate than the BlackJack, which must be controlled with buttons and a scroll wheel on the side.

Also, the Treo’s control pad felt better to me than the BlackJack’s, which was cramped. I kept hitting other buttons on the BlackJack while trying to scroll or select icons.

In my tests, both the Palm and the Samsung sent and received voice calls well. Both also exhibited the clumsiness that is inherent in Windows Mobile — multiple key presses were needed to do simple tasks. Both have basic cameras with resolutions of 1.3 megapixels. (The Apple iPhone’s camera will be two megapixels.)

The BlackJack runs on Cingular’s new broadband data network, called “3G” or HSDPA, while the Treo 750 uses a slower network called UMTS. Oddly, however, in my tests, the Treo was generally as fast or even faster at retrieving Web pages than the BlackJack.

Of these two phones, I prefer the BlackJack. But if you’re in the market for a smart phone and can afford $499, you might want to wait until June for the Apple iPhone. The Apple entry is so full of promise that anyone buying a smart phone in 2007 should at least wait for the full reviews and a chance to try it out.

Email me at mossberg@wsj.com.