iPhone camera lenses can be great addition to your phone and helps you take better and more interesting pictures. Of course you can try to mount SLR lens on your phone but it takes some time and doesn’t give any guarantee you will be able to take some shots at the end.
On Amazon you can find some cool lenses that are made specially for iPhone – telescope, macro/wide and fish-eye it’s all there. Of course you will not be able to squeeze dSLR quality out of iPhone and these lenses, but I can guarantee a lot of fun experimenting.