From the about section of the website: Pinterest is a Virtual Pinboard.
Pinterest lets you organize and share all the beautiful things you find on the web. People use pinboards to plan their weddings, decorate their homes, and organize their favorite recipes.Best of all, you can browse pinboards created by other people. Browsing pinboards is a fun way to discover new things and get inspiration from people who share your interests.
I like this concept.
As of now, you can email for an invite (which I have), but until you get that magical message, you can still check out several things there. I found these to be particularly interesting:
Things to Bake and Decorate
If you want to read more about the site and its concept, click here.
UPDATE: I got my invitation by email at 11:34 a.m. In order to register, you must connect your account through Facebook, so if you are not comfortable with that, then this is not for you. You can search your contacts in Yahoo mail, Google, Facebook, and Twitter to see who has an account. (I found several.)
You have the ability to add a shortcut to your bookmarks bar, so that when you see something you want to "share" it is easy to pin it to your "wall." So far I like it. I can see that this has the potential to become another distraction, so for now. . .the jury is out!