The folks at the Microsoft Hardware Blog have a recommendation for iPad users looking for a blue tooth keyboard:

Our Microsoft Bluetooth Mobile Keyboard 6000 is a great option for the iPad. It’s Bluetooth, so it connects easily without wires, and it has our Comfort Curve layout which encourages a more natural wrist posture over a straight keyboard. It’s also ultra-thin so it looks great and travels well with the iPad.

The Perfect iPad Accessory

That is superb!