I used to hate that question, particularly in high school, when showing my interlocutor the cover of whatever book I was tearing through was almost certain to end that conversation cold. Maybe that's part of why I switched to reading ebooks as soon as it was practical? Anyway, these days I'm happy to let you know what I'm reading; I just added my 1000th book on GoodReads.
The easiest way to explain GoodReads is that it's like Netflix's movie rating and recommendation system, except it can't automatically know what you've got checked out, and it doesn't really do many recommendations, sadly. But it's good about showing you what friends are reading. In other words, it's a social networking site around books. One of several, though the others I've tried seemed clunkier, or too flashy. Goodreads is fairly easy to use, though the UI could use some work in a few places. It's not been especially burdensome to note when I start and finish each book. The best part is that it can keep track of books I want to read.
Rating things on a five star system is not something I'm particularly good or consistant at, nor something I want to spend much time on, but I have painlessly rated about 500 books so far, as well as importing 500 more, unrated, from a list of books I read a decade ago. (500 others from that list failed to import.) I'd like to get a high percent of the books I've read recorded there, so I can a) get a grip on just how many books that is (guessing in the 3 thousand range?) and b) avoid accidental rereads and maybe remember some good books I've not read in a while.
Of course, as when using any service that silos my data these days, I have to worry about getting it back out. For at least the most important bit -- the list of books, dates, and ratings, GoodReads has a good data export capability, though it's a bit hard to find (hidden here) and not ameanable to automated backups. (Aside: Is anyone working on a one-stop utility that can automatically back up your data from all web silos? Needed.)
For the past six months or so, I've been in a bit of a dry spell for finding good new fiction; reading formal book review sites wasn't working for me (most reviews spoil books for me, or just turn me off to them); and ebooks cut down on that library serendipity. I think using this site is helping to break the drought for me, and I'm curious: Whatcha reading?
PS: Thanks to whoever sent me the The Design of Everyday Things (your name wasn't listed). I especially like that it's a used copy. Had that on my wishlist and been wanting to read that forever!