Transcribing with TextMate is surprisingly easy. All it takes is a new bundle with two commands, one that takes you back by three seconds, and one that pauses or plays.
#!/usr/bin/env osascript tell application "iTunes" set currTime to get player position if currTime < 3 then set currSkip to 0 else set currSkip to currTime - 3 end if set player position to currSkip end tell
And here is play pause:
#!/usr/bin/env osascript tell application "iTunes" playpause end tell