Most of the major specs I recommended two weeks ago in my annual spring guide to buying a computer hold true for laptops as well as desktops. That guide can be found at walt.allthingsd.com/guide. But buying a portable involves additional factors, so here are some tips for making laptop purchases.

First, you may want to wait to get that new laptop until later this year or early in 2008. There are a number of interesting new hardware features coming. One is called a “solid-state drive,” or SSD, which replaces the traditional hard disk with a faster drive made of memory chips like those used in digital cameras. Another is a “hybrid hard drive,” or HHD, which combines memory chips with a standard hard disk, for faster start-ups.

Also, more and more laptops will be using light-emitting diodes, or LEDs, to light up their screens — a method that promises to be both brighter and less power-hungry.

You also may want to wait for laptops with a new type of Wi-Fi wireless networking built-in. It’s called “N,” and promises to be faster and to have longer range.

For Windows Vista users, another new laptop feature coming soon is a small screen on the lid called a SideShow, which can display calendar appointments and new emails.

Even if you don’t wait, there are some features to know about that aren’t available on most desktops. One is a built-in Web camera and microphone, highly useful for making video calls and recording videos to be posted online. Another is a feature that allows you to play music, videos or DVDs without booting up Windows.

In addition, if you travel a lot, you may want something called a built-in WWAN, or Wireless Wide Area Network. This is essentially a cellphone modem that makes Internet connections over a cellular carrier.

Another key feature is a new kind of slot on the side of most laptops for add-on cards, like wireless modems. It’s called an ExpressCard slot and, confusingly, it comes in two sizes. Your old-style cards, called PC Cards, won’t fit in these new slots, so unless you want to buy new cards, you might look for a laptop that has both the old and new slots.

Battery life, weight and size remain crucial on laptops, unless you are buying a huge “desktop replacement” laptop, which will rarely leave the house or be unplugged. For everyone else, I recommend finding a laptop that offers at least three hours of battery life on a single charge, without requiring you to dim the screen so much you can’t see anything.

Most laptops cluster around the six-to-seven-pound range, which is fine for occasional travel, or for carrying between classes, or between home and office. But if you are a frequent air traveler and have the budget, shoot for a laptop that weighs four pounds or less and is small enough to use on a seat tray in coach even when the person in front of you reclines.

The most expensive laptops are at the extremes–huge, multimedia machines and ultra-portable models for hard-core road warriors. Most well-configured Windows laptops, with typical 15.4-inch screens, are between $900 and $1,500.

I find that laptops with 13.3-inch widescreen displays make a nice compromise between mobility and power. At the moment, there are very few brand-name models in that size, notably Apple’s $1,099 MacBook, which weighs 5.2 pounds; and Sony’s Vaio SZ line, which weighs 4.1 pounds but costs roughly twice as much. More 13.3-inch models are coming later this year from other manufacturers.

Finally, there’s the perennial issue of Windows versus Mac. Apple’s two laptop lines, the MacBook and MacBook Pro, are very good. They have better built-in software than any Windows laptop I’ve seen and don’t suffer from the security issues that plague Windows. And they can even run Windows software, if you need that.

But the Mac laptops lack some features that are common on Windows portables, such as slots for camera memory cards and built-in cellular modems. And the MacBook even lacks an ExpressCard or PC Card slot.

Among Windows machines, I think Sony and Lenovo make especially well-designed laptops, but almost any name brand would be fine.

Addendum: I’m happy to say there is a new, expanded and redesigned online home for all my columns. It’s at walt.allthingsd.com and access is free. It contains the current versions of the columns with the accompanying videos, plus a searchable two-year column archive and a new blog called Mossblog, which I will update occasionally.

This new column home page is part of a larger new Web site called All Things Digital, at allthingsd.com. In addition to my columns and blog, it contains technology news, analysis and opinion from journalists Kara Swisher, Katherine Boehret and John Paczkowski, and guest blogs from prominent technology figures.

My columns will still be published on The Journal’s main Web site, WSJ.com, which is available to paid subscribers and includes a much larger archive, going back more than a decade.

• Email me at mossberg@wsj.com