Record stores and mail-order outlets
Dusty Groove Fans of jazz and Tropicalia should check this site out; it has the lowest prices on Brazilian imports that I've ever seen.
New Sonic Architecture This mail-order outlet has the largest selection of 70s European rock I've ever seen, with lots of prog-rock, psychedelia and experimental music
Other Music Now one can shop at New York's best record store from the comfort of home.
Artist sites
Radiohead: Planet Telex Contains an amzing collection of Radiohead rarities in Real Audio.
Genres
Kozmigroov "Cosmic/psychedelic" jazz: 70s Miles Davis, Sun Ra and their likes, most of which you'll never hear about elsewhere.
Ian Scott Horst More Kozmigroov, and a little bit of Santeria.
Doug Watson Doug has began to put up an extensive list of the most essential Kozmigroov albums.
Dark Funk Another Kozmigroov site, with an enormous collection of Real Audio stuff (including entire Miles Davis concerts)
Label sites
Miscellaneous
Motion A British E-zine with an extensive selection of new electronica & experimental reviews
WFMU The New York area's best radio station.
Numbers Stations Hear what the CIA does with your tax dollars! This site belongs to a British record label that put out a CD box set of recordings from these stations - the site is probably more interesting to read than the discs are to hear.
Caught In Flux The web version of Mike Appelstein's long-running indie pop zine. Mike also runs the Young Marble Giants site.
Ptolemaic Terrascope The web version of this British zine, which contains extensive coverage of psychedelia past and present.