From a quick note on PHP Magazine's site today:

In a new article, the fourteenth in the Zend PHP 101 series, Vikram Vaswani shows you how to build on the theoretical inputs that you assimiliated from past articles in the series by showing you how to build a fairly straightforward polling system for a web site, one which allows you to quickly measure what your visitors think, as well as make your Website more dynamic and interactive. Read more...

Polls can be a pretty valid method of user interaction with your users, but you have to be careful not to put too much stock in the results. As always, statistics can sometimes belie the truth a bit. They give you example scripts of how to make a simple, single- and multiple-question form to question your users on just about anything. They use a cookie-based security to ensure that the user can only vote once (not 100% reliable, but more trouble than most users would want to worry about to vote more than once). One thing I would have liked to see them throw in would have been a simple graph output of the results - it's just easier for people to glance at and understand a graph than it is numbers and percentages (well, most people...)