Goodreads
I've been looking for a way to keep track of what I'm reading since January (see this post) and finally decided to commit to Goodreads. You can find me (and add me as a friend) there at www.goodreads.com/profile/bookstogether. If you're on Goodreads, please consider adding me as a friend; and if you're not, please consider joining. I would love to see what you're reading.
N.b, the Goodreads widget in my sidebar is showing someone else's books at the moment!
[Updated to add: I switched to a different widget. And, Goodreads is addictive.]