Listography - Create your lists, preserve your story, and stay inspired.

Meetup - Helps groups of people with shared interests plan events and facilitates off line group meetings in various localities around the world.

List Challenges - Earn points for your life experiences. Find lists that interest you, and mark off what you've done.

Google Groups - Google Groups allows you to create and participate in online forums and email-based groups with a rich experience for community conversations.

Bucketlist.org - Log and catalog all the stuff you want to accomplish before you expire.

Eventbrite - Discover Great Events or Create Your Own & Sell Tickets