Are you a potential Google Summer of Code student searching for a project to propose? Consider contributing to diagrams! It's an active project with a small, friendly, and knowledgeable developer community. Contributions to diagrams directly improve people's ability to communicate ideas effectively, and raise the profile of the Haskell programming language. Most of all, it's fun---you get to tangibly experience your contributions in the form of beautiful or useful images.
See Diagrams/Projects for a list of potential project ideas (though note that not all of them may make suitable GSoC projects). We're happy to discuss any of those ideas, or your own ideas, to help you come up with a solid proposal for a project you're excited about---send email to the mailing list.