The Streetglo decals are pretty cool they work great. I can't believe how brightly they reflect. Here are some photos. If I had a gloss black helmet instead of matte you probably wouldn't even see them unless they were activated.
I got the decals from www.streetglo.net the link was posted by marylandmike earlier in the thread. I was surprised how bright they reflect. The website isn't the best you have to keep poking around to find some good stuff.