Requirements: basic css, image editing, basic theming
The fivestar module provides a tidy little voting widget that allows users to vote on nodes. It also provides a CCK field of the type "Fivestar Rating", which can be used to rate a node on multiple criteria.
One of my pet projects, Hill Bomb, requires just this functionality. It's a maps-mashup site for downhill riders, for example skateboarders or mountain bikers, to upload details and maps of awesome hills around the world. Here are the some of the ratings that users can give to hills:
