I got my new L1 just for this purpose. Well actually, this is my excuse for the L1. My avatar is an example of some of the stuff I've done. Some people like to call it light graffiti. Personally, some of my favorites are when I'm partially visible but blurred.
Unfortunantly, it's been raining really hard, so my hobby is on hiatus. I'm almost tempted to do this in the rain.