PartyUP - See videos from the best nightlife venues in your city.
Meetup - Helps groups of people with shared interests plan events and facilitates off line group meetings in various localities around the world.
Discotech - Opentable for nightlife. Tickets, guest lists, and VIP.
TechEvents.co - Tech and startup events aggregator
Partle - Revolutionizing the way people get together
Facebook Local - Discover places to go and events happening near you