It seems like everyone is selling R/C helicopters these days, but most of them can be pretty tricky to fly, and cost way too much to be an impulse purchase.
Not so with the Mini HoverDrone, which will set you back by about as much as a pair of movie tickets. Flying it couldn't be simpler, with just an up and down slider control to think about. The down side is that that's all it does, hover at various heights without moving around the room. The buzzing and hovering is probably just enough for a kid to be really annoying if you're trying to read or watch TV, but at least you won't have to worry about them crashing it into the china cabinet.
The Mini HoverDrone is available now for about $20