1.) Check out the DC5 Yahoo group. You can post messages, chat with fans, and view some picture sleeves, and even hear some rare recordings in the FILES section. (Per Yahoo, you have to "join" the group, which means little more a couple clicks, and no personal information.)
2.) Collect their music. See the discography. Figure out what you're missing, and then trade with other fans for it, or hunt it down in local stores.