Thanks Guys for those replys. I've been playing guitar for a few years and just recently purchased my frist synth (an Alesis QS7) to do some composing and home recording. I really like the idea of an expression pedal as Uncle Dave decribes. Alesis does not seem to offer any kind of expression pedal as an accessory.
Do you know if any expression pedal will work? Is that the same as a MIDI controller pedal?
The only thing I have found so far is an expression pedal by Kurzweil, but its a little out of my price range for now. Maybe I can find something used.