Cvent - Cvent's event management software provides event planners with a complete solution to increase event attendance and decrease event costs.
Virus Cafe - Make a friend in 2 minutes
Eventzilla - Eventzilla lets you sell tickets online and manage attendees from one integrated application.
Upto App - A shared calendar to share and organise your plans with your friends.
Eventbrite - Discover Great Events or Create Your Own & Sell Tickets
Serendipity - Serendipity is a PHP-powered weblog engine which gives the user an easy way to maintain a blog.