Meetup - Helps groups of people with shared interests plan events and facilitates off line group meetings in various localities around the world.
Couchers.org - The new alternative to Couchsurfing. Non-profit. Community-focused. Well built.
Eventbrite - Discover Great Events or Create Your Own & Sell Tickets
Couchsurfing - CouchSurfing is your ticket to explore the world -- from the road or from your own home.
Bylde - Bylde is a SaaS platform you can use to Start, Manage and Grow your groups and communities.
How I Travel - Meet the world's most interesting travelers.