Along the same lines, finding uses for the million white LEDs.

A 7-segment display!

All covered in paste.

All the components soldered down.

And lit up! It's hard to convey in pictures just how bright these are, but you can see the flashlight effect going on on my hand.

It uses a 74HC595 serial shift register, and I've made a module in Upverter so it's super quick to chain multiple together in a PCB.