BEFORE YOU PROCEED, KNOW THIS: I'm a comedian, not a programmer. This things works. I use it myself. But it's not pretty, and could be a little more user friendly.
1. Publish your ShowUpGoUp SMS number
2. Performers text their stage name
3. Your list is built and performers get a response with their spot in the lineup!
It's easy! 1-2-3!
[Psst, right now it's free...give it a try.]