@Maker_of_Things I said random/scrap, but I also have specially home made ones and ones that came with books. I never know exactly when I'm going to start reading, so most often it'll be anything within reach and then change it later.
@benroyce I don't recall the last time I saw a paperback book in a grocery store. I think they replaced them with overpriced shrinking candy bars and national enquirer bird cage liners.