PandoraMedia Platforms Design TeamUsers of this Java-based player enter a song or artist that they like. Then, Pandora creates a streaming “channel” based on the selection. For each new song, users can vote thumbs up or down–and such responses from the user refine future selections. Pandora has a library of more than 500,000 songs and adds up to 15,000 new songs every month. Basic service is free, but an adfree version costs $36 a year. Pandora also can be piped directly to a stereo using Ethernet or Wi-Fi through the Slim Devices Squeezebox player (wireless player shown; $299). Yahoo LAUNCHcastMedia Platforms Design TeamLike Pandora, LAUNCHcast creates a channel based on a user-defined profile of preferred bands. LAUNCHcast’s songs are mono, nonskippable and limited to 3000 per month–those restrictions are lifted for a $5 monthly subscription. Unlike Pandora’s visual ads, LAUNCHcast’s free service plays audio spots between songs. LAUNCHcast doesn’t yet work with Firefox or Safari, and offers only one channel per user–which can force some odd marriages of interest. (Jay-Z and Kenny G on the same station?) AudiobabaMedia Platforms Design TeamThis free plug-in works with either iTunes or Windows Media Player. Instead of streaming music from an online library, it analyzes the music collection on a hard drive. Then, it allows the user to drag and drop a song out of a music player into the Audiobaba window, creating an instant playlist of similar songs–or a continuous-play channel of similar music from your collection.