I know we discussed this thoroughly via email, but the issue cropped up on TA again today so I’ll add a public reply for other players’ reference 
Actual high score tables are currently handled by Openfeint/Game Center, but we’ve heard the suggestion that the map/level select screen could display information about which levels and difficulties have already been completed, and possibly what your current high score is. No promises about implementation yet, but we know some of you would like that feature.