Alkarta - Find happenings in your city.
Skittish - This is no webinar.
Event Finda - Find events near you, and all around the world.
Boost - Boost is an e-commerce for mobile, where users can generate hashtags for products and instantly sell and buyers can tweet to make a purchase
EventsBase - Find the best professional events nearby or globally
Run the World - A platform that enables live, online events