Those Android-powered tablets from Archos are pretty neat, but if you've got a UMPC (like Samsung's Q1UP) lying around, you can try Android thanks to the Android-x86 project. The catch: despite great performance, there are still a few major limitations.
The good news is that you can run Android from a USB drive or Live CD, so you don't have to nuke your current OS.
Kevin over at jkOnTheRun has a Samsung Q1UP, and was able to install an Android 1.6 port originally intended for the Eee PC 701. He says "Android is blazing on a 1.33GHz Intel Core Solo" and suspects the battery lasts longer, too. He was also able to use Wi-Fi, and the Samsung's QWERTY keyboard without problems.
The major glitches Kevin ran into were on the hardware side of things—no touchscreen, sound, Bluetooth, or button mapping support. That's bound to happen when the port isn't specifically geared for the device, but he says he's chatting with developers to make it happen.