Draft Howard Dean has the mailing addresses many of the DNC members. Also, you can check out your online state party websites for contact info that might include phone numbers and email addresses. A lot of these people are also probably listed in the phonebook.
As someone else posted, many of the 440 current DNC members will face re-election as their respective state Dem organizations reorganize this winter, in advance of DNC meeting in DC the first week of February '05, when the Chair will be selected. Further, many of the state committee persons who will vote for the re-election or new member will first face re-election within their local (county/parish/district/etc) Democratic organizations.
This is a ground game, each in their own state. Get together, figure out tactics, let's go forward.