Best computers Laptops shrink, and so do desktops
Computers are going lean, mean, and green, with space-saving profiles, more efficient chips and operating systems, and environmentally friendly designs. The best computers are also increasingly security-conscious, offering features designed to keep your machine and your data out of harm’s reach. Here are some of the latest trends:

Desktops downsize. Many desktop computers are still boxy and bulky, but slimmer models are coming on strong. Dell’s 530S, $630, example, is the smallest conventional design in our Ratings of desktops computers (available to subscribers). Its tower has a 4x16-inch footprint, compared with the more usual 7x18 inches. Other models, including Dell’s Studio Hybrid, starting at $500 without display, are even smaller. This compact desktop uses less metal and plastic than a typical desktop and consumes less energy—70 percent less, according to Dell. (Our tests of a non-entry-level model showed that it used about 60 percent less.)

All-in-ones, which integrate the disk drives, sound card, memory, and more with the display rather than in a separate tower, are also on the rise. Most major brands now have at least one. Five models from Apple, Dell, Gateway, and Sony are in our Ratings of all-in-one computers (available to subscribers). A new HP all-in-one, the TouchSmart IQ504t, arrived too late for the best computers Ratings, but you’ll find our initial impression in the First Look.

Smaller, more efficient laptops. Netbooks, also called subnotebooks, have 7- to 9-inch displays (10-inchers are coming) and weigh about 2 to 3 pounds. They aim to be your second computer, the one you use to surf the Web and check e-mail while traveling, or a child’s first system. But their small size imposes trade-offs. We checked out the 2.2-pound Asus Eee PC 900, $550, and the 3.2-pound HP 2133 Mini-Note, $750, both with 8.9-inch screens. Both systems were sluggish but adequate for e-mail and Web browsing. (Note that neither has an integrated-cellular-modem option, so you’ll have to buy a USB cellular modem if you want to connect to a cellular network.) The Asus is smaller, but it has a cramped keyboard, better for kids than for adults. The HP’s keyboard was much more usable. It’s a good choice for a system smaller than a budget laptop and lower-priced than a slim-and-light.

Processors for a wireless world. Intel and AMD have introduced new chips for laptops and other mobile devices that emphasize energy efficiency and better performance. AMD’s mobile chipset, known as Puma, has a faster Turion X2 Ultra CPU and ATI Radeon HD 3000 graphics, plus integrated support for 802.11n wireless networks. Intel’s answer to Puma is the Centrino 2, called Montevina. It has a Core 2 Duo (known as Penryn) CPU, Intel GMA X4500 graphics, and integrated support for 802.11n and WiMax. Intel’s new Atom processor is slated for smaller mobile devices such as netbooks. Both sets of chips were introduced too late for us to test for this report.

New operating systems on deck. Windows Vista’s successor, Windows 7, is scheduled for release in 2010. Little is known about it, but rumors suggest it will be an "enhanced" version of Vista. Mac users can expect a new version of OS X next summer. Called Snow Leopard, it promises to focus more on performance and efficiency than on new features.

Security features. Eleven of the notebooks in our Ratings of laptops (available to subscribers)  use biometric technology, such as fingerprint readers and facial recognition, as a handy alternative to entering a password. However, those features don’t provide a second layer of protection; anyone can still use a password instead to hack in. You can add both features to almost any laptop or desktop.

Facial recognition, primarily available on Lenovo and Toshiba laptops, uses a built-in webcam to scan your face and compare it with images you’ve stored in the system. While it generally worked in our tests, it wasn’t always accurate, particularly in dim lighting.

Fingerprint scanners are commonly built into laptops but can be added to any computer as a USB plug-in for as little as $35. They’ve generally worked in our tests, though some needed a few swipes to recognize a print.

File encryption is built into the Business and Ultimate versions of Windows Vista (BitLocker), the Professional edition of Windows XP (Encrypting File System), and Mac OS X version 10.3 and later (FileVault). With each, you must enable the encryption, which can thwart thieves or snoops who try to get into your system by requiring them to enter a password. Unless they enter the correct one, your confidential information looks like gibberish. There are also third-party encryption options, including free software from TrueCrypt.org.

The same people who claim they can help police find your stolen car want to protect your laptop. The LoJack $50-per-year service consists of software you can download from the Web or buy at retail outlets. If your laptop is stolen, the LoJack monitoring center can detect the IP address of the router when the computer connects to the Internet. The police can contact the Internet service provider to obtain the physical location of the router. If all goes well, you might find the thief.