Flare Copters are pretty cool. They're little led lights that shoot into the air and flutter down. Bought some off a street vendor one time and ended up playing with them for a long while. They're pretty cool looking at night and could be seen by everyone around you. Here's a video to show you http://www.youtube.com/watch?v=R1UtdwMSSzw
The off brand ones are pretty cheap too http://www.amazon.com/gp/aw/d/B00CV3NN4E/ref=pd_aw_sims_1?pi=SS115