Chris Double has also implemented IO for Nokia phones running Symbian. The whole thing is currently functional on the 7610. Very interesting — IO is a language that draws heavily from Smalltalk, NewtonScript, Lisp, Self, and other languages, borrowing interesting ideas from everywhere. It's a language with prototype-based object orientation and various ideas from functional programming. The language is quite interesting even without a mobile phone. At Planet Lisp you can find the original article.