Front Remote turns your iPhone or iPod Touch into a replacement WiFi remote for Front Row. No installation required on your Mac (Lion not currently supported).
Maybe you bought your Mac before Apple added the IR port. Or maybe you bought your Mac after they stopped bundling the remote. Or maybe your Mac is in a separate room/closet from your TV (no line of sight needed for WiFi). Or maybe you just dont want to carry an extra little thing.
Front Remote works best with WiFi and FrontRow. Front Remote does not work with AppleTV.
Operating Front Remote is similar to operating the real remote:
+/- : used to navigate up and down lists, and used for controlling volume during playback
pressing and releasing previous/next : previous/next track or chapter
holding down previous/next : rewind or fast forward
play/pause : used for selecting from lists, and to play or pause media
MENU : to return to the menu or go up a level in the menu. Also used to start Front Row if it is not running.