Sites

Though its purposes are similar to Last.fm's--to find out what kind of music you like and to stream it to you--Pandora runs entirely in your Web browser and relies on people to suggest new music. As you select and listen to songs on Pandora and give them a thumbs-up or -down, the site provides you with new songs that human music evaluators have determined to be similar in style. At any time, you can search for a particular artist, song, or genre, and Pandora will create a whole "radio station" for you, full of music drawn from the same category.

Pandora's social networking features are lightweight. Your profile's half-dozen, optional fields contain nothing terribly revealing about you, but it's enough to introduce yourself--and you can always elect to be completely invisible to others. I couldn't find anyone I knew on Pandora, and the site doesn't offer to search your contacts for existing users. Other fans of the artists or composers you search for do show up on your screen, though, and you can "bookmark" them, as well, to see what they're listening to.

Facebook's photo-sharing feature is great, and you can list your favorite shows, movies, and musicians on your profile page there, but that's it. iMeem takes the sharing of movie and music preferences a step further, combining Facebook-like socializing with MySpace-style embedded players, playlists, and profile themes. When you join, you enter as little or as much information about yourself as you like into your iMeem profile, including your location, your schools and employers, your music, movie, and TV favorites, and other interests. Then you can assemble a list of friends--either by adding specific friends or by having iMeem search your Web-mail accounts for existing iMeem users. You can search for music and videos that you like and add them to your playlist, enjoy others' playlists, and join or create groups dedicated to particular interests, artists, or genres.

Most of the audio and video available on iMeem consists of short clips (with links to iTunes or Amazon pages where you can purchase a downloadable version), but you can also upload entire songs for your own playback. Musicians and directors can upgrade their accounts to free professional versions, which showcase their work and include an iMeem subdomain (like elvispresley.imeem.com). Real movie nuts looking for a community dedicated to watching and discussing film might want to try Flixster.com instead.