Plug this USB Tentacle into Your Computer and Watch it Squirm (video)
There’s really nothing to this USB device, the Squirming Tentacle. It won’t store anything, but it might just scare off small siblings from messing with your laptop when you leave it unlocked and running. I’m not sure which I prefer; this or the USB Humping Dog, but there is nothing that says you (or I) can have both.
ThinkGeek sells the USB Squirming Tentacle for $25. Buy a USB hub (a powered one since it draws a minute amount of power) and you can have a whole mess of squirming tentacles.