I recently bought myself a MS Wireless Wheel. It takes a little bit of getting used to, but the force feedback is really handy, if a little tiring after a long session. (my wrists were actually hurting the other night after a 4 or 5 hour session)
It's designed pretty well, the wheel sperates from the clamp with a single push putton so you could use it on your lap if you wanted.
Word of warning though, even though they call it a wireless wheel, it still has plenty of wires. It's only wireless between the XBOX itself and the wheel, the pedals are connected via a wire, and the wheel itself needs mains power to run the force feedback (and a pair of betteries for the wireless side of it)
CCL have them for £60 a pop at the moment.