Some people love carrying their big laptops with them. I see them all the time on airplanes, their portable computers barely fitting on those little fold-down economy-class food trays. Some people (me included) favor small, thin laptops. They (the computers, not the people) usually have 12-inch screens and weigh less than three pounds.

New, even smaller laptops are hitting the market. The key word here is smaller. Much smaller. Call them ultra-portables. I’ve told you about the OQO (coming soon, I’m promised). Then there’s the Vulcan FlipStart from one of Paul Allen’s companies.

But first to hit the market are Sony Vaio’s U50 and U70 palmtop-sized computers. Some markets, anyway. Not technically this one. While the U-series computers have been released in a number of places, they're only available in the United States through specialized importers.

Such companies take devices not directly sold in this country, such as computers and PDAs made for the Japanese market, and translate nearly everything into English. One such company, iCube, was kind enough to send me one of their U50s to play with.

These are real Windows XP computers, but they do look and sometimes feel like PDAs, particularly when it comes to size: At 6.6 by 4.3 by 1.0 inches, each weighs little more than a pound.