If I were thinking about doing this with a mac, these would be the first things I'd look at:
- networking over usb / adb (android debug bridge)
- screenrecycler (mac) -
http://www.screenrecycler.com/ScreenRecycler.html
- an android vnc app.
Alternatively there's some android apps made specifically for 'second screen' applications out there - don't recall any specific names at the moment though.