It works a little like Facebook where you can follow people and share ideas. Here's a peak of what I like. Pinterest describes themselves as..
a virtual pinboard — a place where you can create collections of things you love and "follow" collections created by people with great taste.
People use Pinterest to collect and share all sorts of things -- wedding inspiration, favorite T-shirts, DJ equipment. You name it, people are pinning it.
You need to request an invite from Pinterest or someone you know who is on it. Send me an email and I would be happy to send you an invite. This is my new favorite place on the web, a great way to post inspiration.