DemoChoice.org is a useful website where you can conduct STV (and IRV) elections among pre-defined electorates. They’ve just released an application you can add to a Facebook profile. To find it, log in, and search “demochoice.”

They offer two levels of security. For general use, feed DemoChoice a list of e-mail addresses for the voters you want to allow. For more “serious” elections, request that site keys be sent to your voters.

Or just run a public poll for fun.