Social sharing site Pinterest (in invite-only beta launch) is an interesting creature. It is entirely visually driven — that is, you can only bookmark if the site contains an image, and a big one at that. You can create a variety of boards — digital bulletin boards where you pin all the things you find great, interesting and beautiful in the world (wide web, that is). You're encouraged to pin practically anything you find online to your themed boards and to follow other pinners with similar interests to you, comment on their pins and repin to your own boards. It's linked from an original source and with credit. A community like this can be self-sustaining and build upon the boundless options the Internet gives us but with a distinct focus.