Related note: I haven't been asked in a while, but I used to have to boot up my laptop at checkpoints to prove it was a computer. This is a pain because the darn things take three minutes to boot and three to shut down. Now I just claim that my batteries are dead!

I have a universal battery that's about the size and shape of a laptop computer but will plug into any number of different DC devices. I put it into a tray outside my luggage since it ALWAYS gets flagged as "do you have a laptop still in your bag"? It amuses me to watch the screeners try to figure the thing out. Screener: "Open up your laptop" Me: "It doesn't open, it doesn't have a screen. It's not a laptop." Screener: "Well, just boot it up then." Me: "It doesn't boot up. It doesn't turn on. It's a battery. It's not a laptop." Screener: (confused look) "Uh, okay, go ahead then."