I actually just started creating a survey (poll) on my site a few days ago
http://www.vovex.com/forum/
at the bottom there is a "Poll and Satisfation" section where there are a few question polls about our service. I just sent an email out to all our clients with a link to it this morning. Hopefully the results will be good.
I plan on somehow incorporating this into my site so potential customers can view what current clients think about the service.