Sony took the wraps off its Vaio UX50 ultracompact PC at a news conference in Tokyo on Tuesday and our colleague Martyn Williams was blessed with the chance to try out the ever-so-cool looking device. Read on for his verdict.

— It's about the size of a paperback book, so it fits in a jacket pocket, but it runs the full Windows XP OS and is based on an Intel Centrino processor.

Dominating the front of the PC is the 4.5in LCD. This has a touch-screen so you can operate it like the previous Vaio U model as a tablet PC, but you can also slide up the display to reveal a full QWERTY keyboard underneath. The keyboard is backlit, which will be handy if you're using the machine in low light, but I found it a little difficult to use.

The keys are almost flush with the case and don't move much when pushed, so I never really got a good feel for them. They're also small — the entire keyboard is only about 12 centimeters wide — so I constantly worried that my fingers were hitting neighboring keys, although in the brief time I used the computer I didn't get any misspellings.

The position of the "Enter" key at the far right of the keyboard made it difficult to press. This was compounded by its slightly curved shape to match the case.

The screen is sharp and bright. It has 1,024 x 600 pixels resolution so full-screen web browsing is possible, but would be difficult for the poor of sight. Everything in the Windows menus and input boxes was readable — nothing was so small that it became a mush — but I did find myself squinting at some things.

There are a couple of handily located zoom buttons on the right hand side of the case. These helped, although the need to include zoom buttons shows how small everything on the screen is.

That may not be a huge problem because the UX50 seems to be more about fun, on-the-go computing than manipulating Excel files or writing novels. For many users the portability of the device will more than compensate for the small keys and small letters.

Because I had only a few minutes with the UX50 I wasn't able to test other features, although some of the more notable include a fingerprint sensor, built-in camera (just above the main display so you can video conference) and Bluetooth wireless. Sony is selling a companion Bluetooth GPS receiver that feeds global positioning data to the PC.

It's difficult to hold the UX50 in your hands and not be impressed with the amount of technology crammed into it. It compares favorably with Samsung's Q1 ultra mobile PC, which is based on the recently launched Origami platform, and will definitely draw looks when you use it in public.

At Tuesday's launch Sony said there's also a second version on the way. This will use flash memory in place of a hard-disk drive so it's likely to be a little lighter and more expensive. That should launch in the middle of this year.

The UX50 will go on sale in Japan on May 27 and in the U.S. in July. In Japan it will cost around ¥170,000 (US$1,547) and in the U.S. will cost about $1,800, Sony said.

— Martyn Williams (IDG News Service)