http://blog.discoveryeducation.com/blog/2012/03/13/sign-up-genius/
I've started using the free site "Sign Up Genius" http://www.signupgenius.com/ in many areas of my life. My students can sign up for appointments with me (see a sample) , staff members can sign up for professional learning, parents can sign up for volunteer opportunities, etc. The site has numerous templates and three types of survey styles: Munchie Genius, People Genius, and Party Genius.
If you haven't tried it- just sign up for a free account and get started. Users do not need an account in order to sign up for time slots. If users select "I don't want an account" they will still be able to sign up, they just will not get an e-mail reminder.
I recommend you give it a try!
