If UMPCs have not convinced you yet and you want something more powerful them you should check this Tablet PC from Fujitsu: Lifebook T4220, reviewed by TabletPC2.com
The Fujitsu T4220 Tablet PC is an excellent machine all around. It looks good, feels good and has a screen that will spoil you for life. With its bi directional hinge and Core™ 2 Duo Processor this Tablet looks to be an excellent choice for students, road warriors and everyone in between.
The exceptional screen quality of the Fujitsu makes it easy to use for long periods of time and a pleasure to watch a movie on.
While the T4020 did an admirable job with only one gig of memory installed, like anything else running Windows Vista, the T4020 would definitely benefit from a minimum 2 gigs of memory.