Cymbal - Music discovery powered by friends
Calendify - Calendify is an event community where you can share, publish, and subscribe to event calendars. It helps you to stay informed about what you are interested in and what is yet to come.
Noted - Social music discovery
Morse - Create, shout out, and discover nearby events in real time
humit - A social networking app for music sharing and discovery.
Upcoming.org - A simple way to share and discover interesting events