Founders Nation - Find or become a startup cofounder
1up Events - Corporate events as a service
CoFoundersLab - Meet 250,000+ entrepreneurs online
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.
Findnlink - Find people to work with on your ideas.
Facebook Local - Discover places to go and events happening near you