If you want a good tablet, I recommend Android.
The best tablets for the money are the Archos 70 and 101:
http://www.archos.com/products/ta/archos_70it/index.html?country=us&lang=en
http://www.archos.com/products/ta/archos_101it/index.html?country=us&lang=en
A lot of people may hate tablets, but they ARE very useful. When I'm mobile I like to browse the internet via my home computer over WiFi on Archos 5 It. It works great, and with a good connection I can even watch Hulu (Windows 7 only though, XP won't work). The newer tablets I listed above will be getting Android 2.2, which means they will have flash and I won't have to use my home computer for web browsing, but instead just use it for mobile writing with my fold-able keyboard.
I guess thats all useless and can be done by a laptop, but a laptop doesn't fit in my pocket and does have 10+ hours of battery life.