We need hardware add-ons...

I reakon it's high time for companies to start putting out actual hardware add-ons for the iPhone.
What would you like to see? we all have different uses and I am sure there are hundreds of situations where additional hardware would rock.

I am a musician and I'd love them to come out with a 2 octave mini keyboard that you could set on a table and then dock the iphone into to control Pianist or play directly into FourTrack. This would be fantastic as the iPhone is already a proven, tried and tested tool for musicians.