I really want an API that provides info on TV shows. Ever since I heard about the Tommyverse[1] I've wanted to build an application that automatically maps it and lets you play around with the connections between shows, and while it's technically possible to do it with the data IMDB does make available, you can't easily make it public and it's a real hassle.
[1] http://home.vicnet.net.au/~kwgow/crossovers.html