I try to live by the philosophy "A stranger is just a friend that you haven't met yet".

That's kind of how we try to run the site, too! Anyway, I know I've seen a bunch of recs for reading communities around in the other comments, so check some of them out. :)

The advantages of claiming your OpenID account is so you can keep control over comments you've made, both in your journal and in other people's journals if they import them, and control over entries you've made in communities if they're imported. Like, if you'd previously posted to the examplecomm community on LJ, and the admin of that community imports it to DW, any entries you posted there will appear (on DW) to come from your LJ OpenID and you'd have to log into that OpenID account in order to edit or delete them in the future -- which involves being able to log into your LJ account. If you claim your OpenID, though, those posts/comments will be updated to be controllable by your DW account, so you can manage them even if you delete or lose access to your LJ account in the future.