Are there any Web Crawlers for Bitcoin addresses? In an effort to "track the chain" I wonder if there are any Bitcoin web crawlers that specifically look for Bitcoin addresses.

Following on to that question, are there any groups/volunteers/ people using that information to compile a dossier on who has what address?
Well Google, or any other search-engine, already crawls the Web for you. Probably just Googling an address will lead you to the Website where its owner published it, and it'll allow you to find other relevant information related to that address. This of course assuming the publisher of the website actually owns that address. 

The only real way to prove that someone owns an address is for them to actually sign a transaction using that address - in other words: they can prove to you they own an address by making a payment of a specific amount using that address.