Lately I've done a lot of safety-oriented reflective/conspicuity work to go with a big increase in riding after dark and like to be a little creative while I'm at it. These projects are fun (except when you make a mistake. Grrrrr). The Aerostich S.O.L.A.S. tape matches my helmet, so you don't even notice it when it isn't working.
I don't know if anyone is interested except me, but I found a good source of graphic images with a lot of punch. It's a decal place where they have every military badge, but I just like to copy the designs.
http://www.military-graphics.com/badges4.html