I always carry a banana in my pocket.

Because I think it would be pretty cool if some gorgeous woman ever came up to me, winked, and said suggestively, "Is that a banana in your pocket, or are you just glad to see me?", and then I could reveal the banana with a flourish and say "It's a banana in my pocket" and then she'd walk away disappointed and I wouldn't get laid and I haven't really thought this through and I hate bananas anyway.