Meetup - Helps groups of people with shared interests plan events and facilitates off line group meetings in various localities around the world.
Winnie - Great activities and destinations for families
TechEvents.co - Tech and startup events aggregator
Yuggler - Fun activities for kids and family!
Facebook Local - Discover places to go and events happening near you
Jugglr - Moms helping moms. Get things done and earn some money.