Is there an app that changes the SMS keyboard from qwerty to phone pad?

This would definitely be more easy to text and the buttons would be bigger

Having T9 on the iPhone would actually be pretty amusing. It shouldn't be too hard to make a keyboard like that - the Russian iPhone site has some kind of instructions I think. You would add it as an "international" language/keyboard - maybe replace some language you'll never use if it's not possible to add new languages (which I doubt). Then you would just have to replace the autocorrect dictionary. Would require some expertise and several hours of work.

-Vaumnou