Community:
Desert Island Lists - my list of some classic records
Gibraltar - the encyclopedia of prog rock
Italian Prog - dedicated to the italian progressive music of the 70"s
Progressiveears - great progressive rock community site
Expose - longstanding magazine covering progressive rock

Vendors:
CD Universe - the alternative to amazon
GEMM - great place to search for albums
Artist Shop - cooperative music store
BTF - the source for italian prog
Eurock - the place for electronic music
Lasers Edge - great prog mail order site
Musea - this ones for french prog
Synphonic Music - the oldest running prog shop on the "net
Wayside Music - home to cuneiform records

Festivals:
Nearfest - North East Art Rock festival (June)
ProgDay - The Outdoor Festival Of International Progressive Rock (August)

Artists:

 Agitation Free,  Jan Akkerman,  Daevid Allen,  Amon Duul II,  Jon Anderson,  Ange,  A.R. & Machines,  Area,  Art Bears,  Ashra,  Atomic Rooster,  Kevin Ayers,  
 Banco Del Mutuo Soccorso,  Peter Banks,  Barclay James Harvest,  Franco Battiato,  David Bedford,  Birth Control,  Tim Blake,  Christian Boule,  Brand X,  Arthur Brown,  Bill Bruford,  
 Camel,  Caravan,  Clearlight,  Colosseum,  Dave Cousins,  Curved Air,  
 Deep Purple,  
 Eloy,  Emerson Lake & Palmer,  The Enid,  Eroc,  
 Fairport Convention,  Family,  Faust,  Fireballet,  Flash,  Focus,  Edgar Froese,  
 Genesis,  Gentle Giant,  Gordon Giltrap,  Gnidrolog,  Gong,  Pierre Moerlens Gong,  Greenslade,  Dave Greenslade,  Grobschnitt,  Gryphon,  Guru Guru,  
 Steve Hackett,  Peter Hammill,  Bo Hansson,  Happy The Man,  Annie Haslam,  Hatfield And The North,  Hellmut Hattler,  Hawkwind,  Heldon,  Henry Cow,  Hoelderlin,  
 Jade Warrior,  Jane,  Jean Michel Jarre,  Jethro Tull,  
 Kansas,  King Crimson,  Kingdom Come,  Kraan,  Kraftwerk,  
 The Long Hello,  
 Magma,  Didier Malherbe,  Manfred Manns Earth Band,  The Moody Blues,  Patrick Moraz,  
 Nektar,  Nova,  
 Mike Oldfield,  Le Orme,  Osanna,  
 Passport,  Premiata Forneria Marconi,  Anthony Phillips,  Richard Pinhas,  Pink Floyd,  The Pretty Things,  Procol Harum,  Protokaw,  
 Ramses,  Renaissance,  Roxy Music,  Rush,  
 Schicke Führs & Fröhling,  Conrad Schnitzler,  Klaus Schulze,  Sebastian Hardie,  Shylock,  Pete Sinfield,  Starcastle,  Strawbs,  Styx,  Supersister,  Synergy,  
 Tangerine Dream,  Tritonus,  Triumvirat,  Nik Turner,  
 Uriah Heep,  
 Van Der Graaf Generator,  Vangelis,  
 Rick Wakeman,  Darryl Way,  
 Stomu Yamashta,  Yes,