One of our team has recently bought a Logitech Keyboard Case by ZAGG for iPad
The keyboard in the case connects to your iPad 2 via Bluetooth, and the inside of the case is lined to make sure it protects your iPad. The advantage of this case is the form factor - slim, with the same colour as the iPad 2, and the ability to have the iPad in landscape or portrait. You also get iPad 2 dedicated control keys.
Find reviews of other keyboard cases at Mactalk.