Easy Survey Package
PHP scripts that make creating and administration of site surveys easier for non-technical users and helps them gather the results, and view common statistics. Uses a MySQL backend. Once installed administration can be done entirely on the web [Open Source, GPL].
Poll and Voting Script
Template driven script to provide votes and polls on a website.
ScriptRocket Poll
PHP4 Script to create web polls. [Commercial]
UCCASS - Unit Command Climate Assessment and Surve
A PHP based survey maker that's full of features and free under the Affero General Public License.