Ok, I'll be the first to admit that this is stretching the definition of a web service just a bit, but let's give it a whirl anyway! Next thing you know I'll be posting about dogs or something.
The new Amazon UnSpun widgets make it easy for any blogger or web site owner to host polls on their site by pasting in a single line of HTML. The polls can be based on existing UnSpun topics or from a topic freshly created for the poll.
Here's an instantiation of a widget with the "Best Books about the LAMP Stack" poll inside:
You can read all about the UnSpun widget here.