GitSpo - Measure & engage your open-source community
Meetup - Helps groups of people with shared interests plan events and facilitates off line group meetings in various localities around the world.
Devo - Devo delivers real-time operational & business value from analytics on streaming and historical data to operations.
Facebook Local - Discover places to go and events happening near you
Ruby Toolbox - Explore and compare open source Ruby libraries
Eventbrite - Discover Great Events or Create Your Own & Sell Tickets