I used it in combination with the public dumps from IMDB to make a quick on-disk lookup database for use with my favorite (albeit slower) scripting language python.

I didn't have the RAM for holding it all in memory and I was only ever going to do read lookups on it.

It made it very easy to query things like: Given my favorite set of movies, which actors appearing in them have also appeared in the Doctor Who television series?

Just for fun / learning :)