I don't think I'll bother with any of the stuff in my last post because I've just found a few new things.
First I found iTheater which is kinda like Front Row, lets me use the Wii remote and is open source. I was quite pumped about that but soon after discovered Remote Buddy which is even better because it works even better with the Wii remote and actually lets me use Front Row! On a Mac Pro!
I highly recommend it, particularly because the Wii remote is cheaper than an Apple remote, doesn't require a fiddly IR sensor setup, doesn't need line of sight or a short distance because it's bluetooth, has more buttons, etc...
iTheater -
http://www.itheaterproject.com/
Remote Buddy -
http://www.apple.com/downloads/macosx/productivity_tools/remotebuddy.html
Mac Pro - Two 3.0GHz Quad-Core Intel Xeon 5300 series Mac OS X (10.4.9)