I've done this too with a few programs I"ve had over the years. It is indeed fun and interesting to hear songs in their un-natural keys. Playing with the speeds can be fun too, especially with slower songs.
I was just listening to Caroline No which we already know is bumped up a semitone and a bit faster. I was surprised at how positively girlish Brian's voice was when I popped it up a few semitones. Already a sweet vocal, of course, but his phrasing could be that of a girl's easily. IMO it was Murry's genius to suggest speeding that track up and raising the pitch, don't you think? I don't like the other as much.