The postcrossing official forum where you can chat with other members of this project.

Postcrossing gallery for posting pictures of the received postcards.

Postcrossing twitter for quick updates on the project.

Postcrossing Facebook group for the users of this big social network.

An orkut community around postcrossing.

The famous and only Bookcrossing Project.

Little things on big adventures.

Allows you to track your Euro bills around the world.

This project is making 1000 journals travel around the world.

A French project that allows it's users to exchange surprises.

The postsecret project allows people to reveal their secrets using postcards.