Meetup - Helps groups of people with shared interests plan events and facilitates off line group meetings in various localities around the world.
Stadium Help - Concert presale codes, tickets, setlist, media & more
Eventbrite - Discover Great Events or Create Your Own & Sell Tickets
Journy - Tastemaker-driven concierge to plan your perfect trip
Bigtent - BigTent is a web-based organization and communication portal for groups.
Sygic Travel Maps - Itinerary planner for independent travelers