SimilarWeb - SimilarWeb.com is a website analysis tool that gives you analytics information for any website.

Meetup - Helps groups of people with shared interests plan events and facilitates off line group meetings in various localities around the world.

Site Rank Data - View historical rank information of websites via time series charts.

Eventbrite - Discover Great Events or Create Your Own & Sell Tickets

Quantcast - Quantcast Corporation is a digital marketing company that provides free audience demographics measurement and delivers real-time advertising.

Bigtent - BigTent is a web-based organization and communication portal for groups.