Shapr - A completely free way to build your professional network.
Eventbrite - Discover Great Events or Create Your Own & Sell Tickets
Event Hunt - Startups and Tech Events Curated By Locals
Cvent - Cvent's event management software provides event planners with a complete solution to increase event attendance and decrease event costs.
GetReal - Meet new people, in person
EventMobi - EventMobi is an interactive mobile event app, audience response and engagement platform for conferences and trade shows.