If you want to make a simple, but sexy poll, you can use twtpoll for free. Unfortunately the results are displayed as a flash animation.
In the interface you can set the questions and if the answer should be unique or multiple. Also an expiration date is possible and you must not keep it alive forever.
The best to use for twitter is, that it generates a short URL direcly from it’s own host. That is is looking like this
Test it out to get quickly and easily public without complicated setup surveys.