From Postcrossing:

"The goal of this project is to allow people to receive postcards from all over the world, for free. Well, almost free! The main idea is that: if you send a postcard, you will receive at least one back from a random Postcrosser from somewhere in the world. "

Here are four basic logos for the site:

1. Flat logo
2. Bevelled logo
3. Bevelled logo with reflection
4. Bevelled logo with drop shadow.

Enjoy!