Thanks koyaanisqatsi that looks great, the code is so short! I will try this on my own board soon.
My only question is what do you do about if you need to run other code? If you are using the Arduino for anything else (LCD, I/O, etc) won't it mess with the timing? I just ask because this was why I started to use Timer1 so I ensured the dimming function worked as a software interrupt and my regular code would not interfere.
Let me know your thoughts. Great work! I guess I should get working on a final design now. In your testing were you getting much buzz from the Triac? I am trying to figure out how to silence it a bit, maybe an inductor but I need to pick a few up to try it.