Sony Vaio VGN-UX390N

In designing its VAIO Micro PC VGN-UX390N, Sony has condensed a standard notebook computer into a device only a little larger than--and about twice the weight of--a BlackBerry. And it did a good job, with two critical exceptions: The 4.5-inch display is too small for easy viewing even at arm's length, and a finger on the keyboard is a typo waiting to happen. If you plug in an external monitor, a keyboard, and a mouse, however, you'll see the better half of the UX390N's split personality: An ultramobile PC that's right at home on your desktop.