RoomForTea - A female-friendly housing network in London, UK.
Meetup - Helps groups of people with shared interests plan events and facilitates off line group meetings in various localities around the world.
tripcake - Doodle for travel plans with friends
Event Hunt - Startups and Tech Events Curated By Locals
Magpie - Female travelers club - meet women like you when you travel
Eventbrite - Discover Great Events or Create Your Own & Sell Tickets