How can I use my device as a wifi keyboard and trackpad for my computer? I have three different MBP's that run XBMC off and on, connecting to our home theater systems.  Is there an app that I could install on my droid and the mac's that would allow the droid to act as a keyboard and trackpad when the MBP is connected to the TV?  

I know about XBMC remote and it's great, however I'd also like to be able to use the machine for web browsing or basically anything I could do with it in my lap (albeit slower with a small keyboard).
Gmote will let you control your computer over wifi via your Android phone.  It basically treats it like a keyboard/mouse.