Mixily - Hosting your event just got easier.
Cvent - Cvent's event management software provides event planners with a complete solution to increase event attendance and decrease event costs.
Eventbrite - Discover Great Events or Create Your Own & Sell Tickets
Eventzilla - Eventzilla lets you sell tickets online and manage attendees from one integrated application.
Balloon - A drop box for your Dropbox
Attendify - Develop relationships at the events that you attend by creating smaller events with just a few people.