I've had one of the litte Sony UMPC machines for ten months now, and it has been great. All my apps right there in my pocket. (Granted that it has to be a fairly large pocket, and it's unnerving how many people ask if that's an ultra-mobile PC or if I was just glad to see them!)

Anyway, it's nice and zippy when running XP, enough oomph to develop .NET code or C++ using the scaled-down Express products from Microsoft. They're all I really need when I code on the run, so no complaints.
The video is speedy, able to play back full-screen (1024x600) at 60fps. Seriously impressive. And 3D games are pretty amazing.
The only things I can't stand after these ten months are the short battery life (realistically about 1.5 hours), and the somewhat obnoxious keyboard. It's QWERTY, but I wish it were a true staggered layout like a normal keyboard instead of this grid thing:

So now there's some competition emerging in this segment of the market; these two contenders have stepped up to the plate:
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| The new OQO 02, released in January '07 |
The new Flipstart, to start shipping any day now |
The OQO has the faster chip and is a little smaller, and the FlipStart has a little touchpad, larger keyboard, and longer battery life. Decisions... Decisions...
Pretty good times to be a gadget freak. I might jump in and pick up a FlipStart because some folks are reporting that you can lay the thing on your lap and actually quasi-touch type with it. That's a big benefit. And battery life is supposed to be a little longer than my "old" Sony. If any of these folks releases a machine that uses the new Penryn core (the 45nm stuff) then it'll have even better battery life, and I'll definitely be onboard.