This is a question I'm very interested to hear an answer to. I've started dabbling with Objective-C and I don't like it much; it would be very sweet if I could write apps for the i{Pad,Phone,*} in a Lisp-like like language.

Well, the revised version doesn't fully forbid them. It would be interesting to see what you must go through to get Apple's approval. I would bet people using Lua are pretty well set due to its use in video games.