I was at Target looking around their little $1 nick-nack section and found a cheap kids toy ring. It's soft rubber with a circuit inside that flashes four LEDs rapidly when powered on. For that $1 and some desoldering you can get a nice bright blue LED and have the other 3 spare LEDs for more projects. The board is fairly easy to get out of the ring as there is a small hole that can stretch very wide to work it out. I have yet to really check their sizes, but I know they're small round non-SMT LEDs attached to the board. There is also a small rubber contact button on the board that is the on-off button. It could be useful for a custom button for a project as well. I have plans of changinmg my iMacs power LED to blue, and maybe getting a second ring to use a second blue LED as the sleep color, unless I can somehow just wire the one in place of the bi-color that is stock.