Is there a modules "wish list" anywhere? I'm new to Drupal, and right now my job consists mainly of site-building. But I'm a PHP developer, and I'd like to get into module development. The problem is, anything I could think of to do has most likely already been done! Is there any kind of wish list maintained somewhere (on drupal.org) of modules that people wish would be written?
Check out the Contributed Module Ideas group on groups.drupal.org.

The Google Summer of Code group can also be a good source of inspiration. Some of the ideas may not be big enough to sustain a student for the entire summer, so they don't get picked up otherwise.