Bluetooth mouse/keyboard app idea, has it been done?

[Chou87]

I had an idea for an app that uses the phone's camera as a tracking device in the same way an optical mouse works. It'd be interesting to be able to hold your phone over (not on) a textured or complex black/white patterned surface. The camera sees the surface and the app tracks which direction the pattern is moving to tell it which way to move the mouse. Using on-screen buttons (customizable button configurations/layouts maybe?) as the mouse buttons. Or use the volume rocker

Connect this over bluetooth or wifi for a quick android based mouse for your laptop or pc... Has it been done? Can it be done?

 

[PensHockey]

I know touch screen android devices can be used as a mouse touch pad connected to your comp.

 

[Chou87]

Well yeah, but I already have a multitouch trackpad. Having two trackpads isn't going to help my situation