I'm currently obsessed with Pinterest. I blame Janet. Here is my profile link if you want to see what I've been pinning....
Think about having a bulletin board where you tack up all the stuff you like. But multiply it by OCD and the internet, and you have Pinterest. Any time I find something I like online, I have a button on my browser to pin it. You can have a bunch of categories, such as funny stuff, foods I want to make, decorating ideas.
Here's something I pinned today. (click the picture for the recipe)
It's now saved on my Om Nom Nom board. If Janet, who I still blame, sees that I pinned this and likes it, she can repin it to one of her own boards, or just comment on it about how brilliant I am. So there's a bit of community fun built right in.
Some of my boards are very functional, such as the food one where I have pinned a ton of tasty looking Weight Watchers recipes. Other boards are just for fun, like the Mischief Managed board where I pinned a bunch of Harry Potter stuff that amuses me.
Enjoy, and happy pinning!