OK, now I'm thinking about nuclear features, like pnut crawling any links posted to Global, and providing an interface to what it finds. Just as a source for the crawl, but also as a nice indexing feature. Want to be able to look into a website? Post the link. A little while later it'll be in the index.
Probably lots of sticky legal/customer service things with crawled indexes. Might as well play with it not in any official way, just to see what I can come up with. The goal is to decontextualize whatever it finds.