I wasn't looking for another place to visit online, but when Angela Hunt sent me an invite to Shelfari, I had to check it out. Bibliophiles beware---this is a great way to waste your time! But it's fun. Basically, it's a way to display all the great books you've read recently (or that appear on your shelf) to your friends. People can comment, tag, rate books, you name it. You can also add your shelf to your blog (which I've done but am still fooling around with). Everything's very easy and aesthetically pleasing. Check out my profile here, if you're interested.