Whenever I see a movie with a couple of my single dude friends, we make little comments about the previews to each other. I'll usually whisper either "Super going to see it!" or "Stuuuuuuuuupid." One of my friends will shake his head in disbelief through most of the previews, which is a pretty good indicator that I'll never get him to go see those particular movies.
Sometimes, after the movie we went to see is over, we'll talk about which of the previews interested us. I'll usually bring up a chick flick that looked good and one of the guys will say, "Oh, I knew that was lock the minute I saw it" meaning, he knew it was a lock for me. Well, we haven't collectively seen the previews yet for Leap Year, but when we do, it's going to be a lock.