I know that they're illegal, but what I'd love to do is to get a small low power cell phone jammer. Turn it on and drop it into one of my pannier bags. Imagine the looks on people faces as they're in the middle of one of those "oh so important" phone calls and their phone suddenly dies on them? Only to a few seconds later to come back on. Or while we're at a red light their phone goes dead and than once they clear the intersection it starts working again?