The UMPC or the Ultra-Mobile Personal Computer was a new technological trend in the 2000s. Following the 90s where clunky and beige was the norm, pc makers created a frenzy of making everything smaller and smaller, eventually leading to these handheld computers. Although at the time they were perceived by many to be the future of computing, the trend died out rather quickly, probably due to the fact that it was not as convenient as one may think and it definitely was not much cheaper than a full size pc. The most notable models are the OQO models 1 and 2 or the Sony Vaio UX both of which mostly ran Windows XP but later ran newer OSs such as Vista. I think these things are very neat and really show a testament of technological advancement in the 2000s! :-)