I built a similar thing for a talk my co-founder and I gave at TED, we needed to use a Gyroscope in an iPod Touch with an iPad and so I initially used WebSockets to proxy sensor readings at about 60Hz (from the ondevicemotion HTML5 APIs). It worked pretty well, but ultimately I ended up writing a bit of C to send the data over UDP directly to the client so that I could skip the web server.

Even then, everything failed on stage when there was too much interference to send anything over WiFi :(

Works great but it would be nice if you could also use the the movement on the iPad as a relative start point from where the mouse cursor is on the computer screen... you know, just like a notebook's touchpad.

For example if a slide my finger from the middle of the iPad to the bottom right corner, the mouse cursor on my computer is moved from the middle of the desktop to the bottom right corner, no matter where the mouse cursor position's when the action starts. There should be a checkbox (relative movement or something) so when you slide your finger on the iPad the mouse cursor on your computer uses its current position and moves with your finger, it should not be repositioned where your finger first touches the iPad screen.

Also, one tap should equal a left click, and maybe two taps a right click.

Also, maybe you can get a screenshot of the desktop instead of the white background on the iPad? Then you would have something similar to a VNC server-client thingy, which I'm using right now on my iPad and computer :)

I love little trinkets like this. Nice work. On a side note, I've been staring at the mouse on my desk for 2 minutes now, and it's still not moving.

There's also fingerpoken by Jordan Sissel - https://github.com/jordansissel/fingerpoken