I work a lot with visual studio in a virtual machine, and on a mac, the function keys just get in the way of debugging and what not.
I needed a way to quickly enable and disable the mac function keys. Found my solution over here:
Get FastScripts http://www.red-sweater.com/fastscripts/
and one of these AppleScripts depending on your OS version
Snow Leopard (works on my mountain lion too):