Here is the homepage of my latest mod:
Dancing Device LED Homepage
I included photos, an mpg, & a brief guide on how to make it. It is very cheap & easy to make (see schematic below, 4 parts). It hooks up to a device activity LED driver (like a HDD or NIC LED connector on a mobo) & gives chasing lights that advance with device activity. The movie I uploaded doesn't do this mod any justice.