Shoutbox

Hi
I was wondering, how can I add a poll to my website? It can be either a service or a code but I only got php. It will need theese features:

-Only allow each person to vote once
-Free
-As little ads as possible, if possible none at all
-No sign-up required for the voters

- must have cookies
- pscode??? or similer
- pscode... just edit
- cookies

just search pscode for poll and look if it says cookies

http://www.pscode.com/php