Yea Kat, I suppose Caitlin is pronounced something like Kathleen, without the th.If you remember, Dylan Thomas' wife was Caitlin.As someone said earlier the clerks at Elis Island had a lot to do with mispelling names, but Caitlin is not a mis spelling .It's a clear mispronounciation.And here in Ireland,they're now starting to name children Kate-Lyn, as a result of the influence of day time soaps (a friend rather uncharitably refers to these Americanised names as "single mother names") Don't forget in America they've even got women called Sean (or Shawn, or Shaun or take your pick of any spelling you fancy)