I was looking for a way to control iTunes remotely. An inexpensive alternative to Keyspan or other remotes is the ATI Remote Wonder remote control -- you can buy them on eBay for about $20. The remote is RF based, so it works through walls.
The nice part about the remote is that the software lets you remap any key to almost anything, and it comes with preset actions you can choose for common apps like iTunes, DVD Player, and QuickTime.
By creating tiny AppleScript apps like the one below, I have assigned keys 1-9 to various playlists, so I can start iTunes and go to a selected playlist from a room in my house far from my computer, and then play, pause, skip songs, switch playlists, etc using the remote.
tell application "iTunes"
tell playlist "Classical"
set shuffle to true
play
end tell
end tell
The AppleScript will also start iTunes if it is not running.
Mac OS X Hints
http://hints.macworld.com/article.php?story=20060403195632927