IMDB

Unfortunately, IMDB doesn’t seem to have any real API. You can, however, download a bunch of the data in a flat file format. The problem is, the files contain a notice saying:

Specifically the files may NOT be used to construct any kind of on-line database (except for individual personal use).

I was hoping to make a little web app where you list a few TV shows and/or movies, and it build a graph of the actors they have in common. There are certainly other interesting network analysis things to do (some of which have to do with Kevin Bacon).