The Nokia N800 internet tablet is compatible with wireless keyboards that use the Bluetooth HID standard.
This video tutorial shows you how to pair a Bluetooth keyboard to the N800 and how to use the keyboard once it's connected. It also shows how to add your own keyboard shortcuts so you don't have to keep using the touchscreen when the keyboard is connected.
You can find more tutorials like this by going to www.neoncherry.com and clicking on "Internet Tablet School".