Meetup - Helps groups of people with shared interests plan events and facilitates off line group meetings in various localities around the world.
Evercontact - Your contacts always up to date and automatically with Evercontact.
Facebook Local - Discover places to go and events happening near you
CONTACTBOX - CONTACTBOX combines the simplicity of an address book with effective functions of a CRM system.
Eventbrite - Discover Great Events or Create Your Own & Sell Tickets
Pobuca Connect - Connect with your contacts.