Create Digital Music - "A webzine for digital music making. Includes product reviews and announcements, music-production tips and an active community offering helpful music-making advice."
Muxtape - "Lets users build playlists out of MP3s they upload. Share your hand-crafted mixtapes with friends, or listen to others' from the Mixtape homepage." Currently unavailable as they "sort out a problem with the RIAA." Try OpenTape instead.
RadioTime - "Lets you tune in to the online streams of terrestrial radio stations, whether they're in your neighborhood or across the country."
Songza - "A search engine that gives you easy access to streamable MP3s across the Web. Enter a song or artist, and Songza serves it up for free."
TheSixtyOne - "Discover, download and upload new music, as well as build playlists of streaming tunes online. Utilizes a Digg-style approach to finding music and a game format that transforms listening to new music into a fun, massively multiplayer adventure."
WolfGang’s Vault - "One of the largest collection of live concert recordings and music memorabilia. Grants free streaming access to vintage recordings of thousands of live shows by rock legends like Clapton, Hendrix and The Who."