Meetup - Helps groups of people with shared interests plan events and facilitates off line group meetings in various localities around the world.
Sprig - Delivering locally-sourced, seasonal, sustainable lunches and dinners.
Eventbrite - Discover Great Events or Create Your Own & Sell Tickets
UserVoice - UserVoice integrates easy-to-use feedback, helpdesk, and knowledge base management tools in one platform that empowers users to speak and companies to understand.
Bigtent - BigTent is a web-based organization and communication portal for groups.
User Interviews - User Interviews is a tool to recruit participants for product tests and market research.