Netbooks: These small, cheap laptops have become very popular since they were introduced two years ago. Originally sporting tiny 7-inch screens, netbooks have been creeping up in size. This year, most of them have screens between 10 and 12 inches and keyboards that are more comfortable for adult users. What's lagged is processor power: Most netbooks still can't play Hulu or YouTube videos without stuttering.
That's finally changing as netbooks are getting more powerful graphics chips and Adobe is upgrading its Flash player software to take advantage of them. We tried an HP Mini 311 ($400 list) with an Nvidia ION graphics chip and found it easily played DVD-resolution TV shows from Hulu. A Toshiba T115 ($450) with an Intel graphics chip played lower-resolution shows fine, but choked at DVD resolution.
Both have 11.6-inch screens and weigh a little more than 3 pounds. The Mini runs Windows XP, while the T115 runs Windows 7 Home Premium, for an updated look and greater ease of use. When playing high-resolution video and accessing the Internet over Wi-Fi, the Mini's battery lasted 3 hours and 35 minutes, compared to 3 hours and 50 minutes for the Toshiba - very respectable scores but not at the top of the netbook range. In less taxing use, both would last several more hours. The HP model is widely carried in stores, while the Toshiba will be easier to find online.
Ultrathins: The big news in laptops this year is that power-thrifty "ultra-low voltage" chips that require little cooling have been coming down in price. That means that light, skinny laptops with amazing battery lives are available for $600 to $1,000 - less than half of what they were going for a year ago.
We tested the Asus UL80Vt ($850), which lasted 4 hours and 30 minutes in our challenging battery test - an astonishing figure for a machine that has a large screen (14 inches) and is still light, at just 4.6 pounds. In less taxing use, it could live up to the manufacturer's claim that it could run for up to 11.5 hours. A good graphics card and a DVD drive make this a formidable, 1-inch-thick entertainment package. It also contains an innovation that's showing up in several laptops: a button that boots up the computer in eight seconds. That launches a different operating system, not Windows, but it does have a Web browser, and it could be useful for quick e-mail checks and the like. Only complaint: the mouse button is too stiff. This computer is best found online.
The recently updated Apple MacBook ($1,000) is slightly heavier and thicker, with a smaller screen. But it has a full-power Intel chip, making it much more capable at heavy-duty applications such as video editing. The slick and friendly software and huge touch pad make the job easier. Sold at Best Buy and Apple stores, and on Apple's Web site.
Full-sized laptops: These haven't improved as much as smaller ones lately, but the release of Windows 7 has inspired manufacturers to try something new: touch-sensitive screens. This sounds like a gimmick, but use one and you'll probably think otherwise. It's nice to be able to bypass the touch pad or mouse and "click" on a Web link simply by touching it. We tried the Acer Aspire 5738PG, which has a 15.6-inch screen, and found it a pleasure. However, at $800, it's about $120 more expensive than an equivalent non-touch model. You'll have to decide if the premium is worth it.
This is a powerful, 6-pound machine in the "desktop replacement" category. While running on battery power, it lasted just 1 hour and 35 minutes. Find it online.
Touch desktops: Hewlett-Packard Co. has been making desktop computers with built-in touch-sensitive screens since 2007. Now that Windows 7 is out and includes better support for touch screens, other manufacturers are jumping on the bandwagon and prices are coming down.
We tried a Gateway One ZX4800 with a 20-inch screen. It can be had for as little as $600 online or at Best Buy stores. For a desktop computer, it doesn't have a powerful processor, but it breezes past the Hulu test and all regular tasks. Only 3-D gaming and high-definition video editing would really tax it. A model with a bigger screen and a beefier processor costs $1,300. The included touch-based games aren't much fun, but Web browsing by touching the screen feels natural. It comes with a wireless keyboard and mouse.
On the high end, the Sony Vaio L Series has 24-inch screens and costs $1,300 to $2,000. We tested the most expensive model, which has a powerful quad-core processor and a Blu-ray drive. It also doubles as a TV, with inputs for an antenna, cable box or game console. It even comes with a remote. That makes it a true "all-in-one" device and a great pick for a dorm room, if you can afford it. Easiest to find online.