There's a nice video up on YouTube of someone demonstrating a great usage of the UMPC: using a UMPC to control a home automation system.

There's some really interesting ideas raised in this video. Being able to see who's at the front door and letting them in without getting up sounds really enticing. Being able to access and control all of your entertainment media also sounds great. The thing is, the UMPC is so versatile that it can do all of the home automation without breaking a sweat and then go on and function just like a regular computer running the software applications that you want wherever you want.