I had a N900 and used to write lots of code in nano. It had python, ruby and PHP and was a great tool for quickly coding ideas or scraping and grepping web APIs. It ran vi and emacs too but I never really used them.

Now I have an Android device that's 5x faster and 10 more usable as a phone but I've only written about 10 lines of code in total on it's virtual keyboard. Hoping my next phone combines the best of both worlds.