You may be aware of Touchpad pro.
This uses VNC to allow you to use your iphone as a trackpad for your Pc or Mac that has a VNC server running on it.

Out of interest, would it be possible to run a VNC server from your phone, and control it from your PC?
This would mean we could use our PC Keyboard and mouse, or a games controller connected to our PC to control snes4iphone, psx4iphone etc..

Think about it