Bright Bike DIY kits cover your bicycle in easy-to-apply design-savvy ultra reflective vinyl for safety. It is like covering your bike with a big stickers that turn ultra-bright in headlights. The retroreflective vinyl is the same material used on the backs of running shoes, but with colors. The kits greatly improve night visibility and thus bicycle safety.
I got the blue pinstripe set and I love it - a bright source of light, like a car headlight, hits your bike, and you light up like a christmas tree. It's especially pronounced at night, and as cool as this picture is, it doesn't do it justice. Check out the video on their website for a nighttime demonstration.