Petscii Forums - Discussion boards for TelBBS, Quantum Link Reloaded, DTVHacking, Retrobits podcast and programming. - http://jledger.proboards19.com/
Yahoo! Groups : c64 - A mailing list for any and all Commodore 64 related discussion. - http://groups.yahoo.com/group/c64/
Yahoo! Groups : classiccommodore - Open to all who wish to preserve the knowledge of classic Commodore VIC20/C64/128 line of computers. - http://groups.yahoo.com/group/classiccommodore/
Secret Society of Commodore Coders - Message board for discussing BASIC 2.0, BASIC extensions, and ML on the stock C64. - http://ssocc.proboards45.com/
Commodore 64 Forums - Commodore 64 message board with forums for hardware, software and emulators. - http://commodore-forums.wabbit-wion.nl
Lemon's C= Forum - Emphasizes games but also has forums for general C64 news, new releases, tech support, the demoscene, and a marketplace for buying/selling/trading. - http://www.lemon64.com/forum/
cbm-hackers - Searchable archives of a mailing list devoted to programming the Commodore line of 8-bit computers. - http://www.softwolves.pp.se/misc/arkiv/