I can't seem to find the right spot for a new mod suggestion (thought I saw a link here somewhere), so I’ll post a quick thought here.
Since we don't have much room in the 360 controller, and the 'rumble' motors take up a lot of space, here's a idea.... (patent pending, if you can do that with thoughts/ideas =) )
What's to say we can't replace those motors with a circuit board that has a piezo buzzer on it that does the vibration? Current cell phone technology uses the piezo buzzer to give us this vibration feedback.
We could design the board to fit into where the motors sit, and take up 75% less room. If the circuit was designed well, it could also save some battery life.
I don’t have the electronics background to design this circuit (won’t stop me from trying though).
Thoughts?