Eventbrite - Discover Great Events or Create Your Own & Sell Tickets
Meetup - Helps groups of people with shared interests plan events and facilitates off line group meetings in various localities around the world.
Eventzilla - Eventzilla lets you sell tickets online and manage attendees from one integrated application.
Splash - Anyone can create a Splash event, whether you're a company hosting a single event or an individual hosting a personal event like a birthday or wedding. Get Started for Free. Text goes here. X. Full Event Program.
Meetabit - All the local tech and startup meetups in one place - easy to organize & attend
EventMobi - EventMobi is an interactive mobile event app, audience response and engagement platform for conferences and trade shows.