Eventbrite - Discover Great Events or Create Your Own & Sell Tickets
Palaround - Meet people you should be friends with.
Cvent - Cvent's event management software provides event planners with a complete solution to increase event attendance and decrease event costs.
Digg - Digg delivers the most interesting and talked-about stories on the Web right now.
EventMobi - EventMobi is an interactive mobile event app, audience response and engagement platform for conferences and trade shows.
quippd - quippd is a social news site that anyone can edit.