Learn to code PHP and write one yourself. The easiest way to implement it would be with a mySQL database to store the questions / answers and how many votes they have - then use cookies to remember who has voted and stop them from voting again (remember that this is not 100% garaunteed as anyone not using cookies can vote many times).
You can't really come on a forum like this and expect someone to write the script for you. If you want a pre-made poll script there is a good one on this site called phpPolls:
http://www.phpwizard.net/projects/phpPolls/
Alternatively read this and learn how to write one in PHP yourself 🙂
http://forums.gameplay.com/showthread.php?threadid=232181
Cheers,
Simon
