Serendip is a new music discovery service that builds you playlists based on what your friends are playing. Once you have signed up, Serendip turns you and all of your friends into DJs, and gives each person a page stuffed full of music.
The service first asks you about your favourite musicians and lets you follow other Facebook or Twitter friends who are also using Serendip. You can dive in and listen to music they've posted on Twitter or Facebook. Your playlist is at the top of the display, the music video for the song is at the bottom, and the friend who shared the song can be seen on the right. If you like the song, you can give them a "Rock On" signal, which lets them know you liked it and reshares the song (if you want it to). You can also "air" your own songs to followers from the search bar at the top of the page.
Serendip does a great job of finding relevant songs, despite only being a new service. Your DJ page grows as you use it and connect with more people. It has a lot in common with previously mentioned This Is My Jam and The Monstro, another music discovery app we love. If you're looking for a tool that uses both Facebook and Twitter though, this is a good option. If you give it a try, you can find my profile here.