I included my .pde sketch, but the meat is in the library.  Just make a <arduino sketch dir>/libraries/Firefly directory and add in the Firefly.h and Firefly.cpp files.  You should be able to just import the library from the Arduino IDE.

I'm using little SMD RGB LED's in the jar, run off of a LilyPad.  So far, it's pretty neat - but there's some stuff I want to add for sure :

1. More fireflies (gotta figure out how to mux/demux RGBs for that)
2. Some basic threading.  It'd be cooler if the flies could act independently such that they could maybe fire off at the same time.

Video of first draft : http:https://www.youtube.com/watch?v=ecCJJR7UZEE

Comments/suggestions always welcome.