Meetup - Helps groups of people with shared interests plan events and facilitates off line group meetings in various localities around the world.
Intro - Personal branding theme for developers.
Eventbrite - Discover Great Events or Create Your Own & Sell Tickets
PullContacts - Quick and easy email address, phone number and social media link scraper.
Bigtent - BigTent is a web-based organization and communication portal for groups.
Open Cult - A place for people with common interests to meet IRL.