If you're only going to run one 5k this year (or maybe even in your life), you should check out the Color Run. I know a lot of people who have done Colors Runs in other cities (including in Memphis last week) and they say they're a blast! The caveat is that the often sell out (some events after the Little Rock run are already sold out).
The concept is similar to what they do in India for the Holi festival in that runners (and walkers are welcome too) are decorated with powdered dye at you at various points on the course. Volunteers throw the dye at participants (and at the end, everyone gets to join in). Runners are instructed to wear white, and I've heard other participants mention you might want to bring a towel or plastic sheeting for the drive home.
If you're worried, the majority of the color gets tossed at the end of the race, so you can avoid the big dumping if you want to...but where's the fun in that?
Little Rock's Color Run is November 10 and it will take place in Riverfront Park. Even if you don't run, you might want to toss on a white shirt and visit the festivities. You could also volunteer and coat people with colors. Registration is $50.