The extra p makes Tripp more of a name and less of a Trip. Usually a nickname of a boy who's a third, but Tripp is sure to get more attention in its own right now as the name of SarahPalin's daughter Bristol and LeviJohnston's son.
Tripp Campbell, main character on TV's "I'm in the Band" William "Tripp" Vanderbilt III, character on TV's "Gossip Girl"
Tripp McConnell, character on TV's "Eerie, Indiana"
Tripp, main character in 2006 film "Failure to Launch"