We're not sure yet what we want to extract. It's a bit of exploratory programming for a research group, and we won't really know what will turn out to be interesting until we've got a first draft implementation. We'd like to be able to do things like find the shortest path between two Web pages, find the longest shortest path between Web pages, find how many pages link to a page, how many links a page contains; standard graph theory sort of stuff, which is why we started with the Graph class.