I am known as something of a practical joker around the office, using Sellotape to fix phone handsets together, setting staplers in jelly and making prank phone calls to my colleagues on a regular basis.
One of the ways that I have caused much mirth in the office during the course of my career is to hide whoopee cushions under people's cushions that they place on their office chairs in order to relieve back pain and make themselves more comfortable.
If you haven't used a whoopee cushion before, let me enlighten you! They are rubber bags that have a loose airhole into which you blow air, and then when your unsuspecting victim sits on it the air is expelled in such a way that it simulates massive uncontrolled flatulence.
This is a joke that never gets stale. The more sombre the occasion, and the more important the victim of this joke, the bigger the laughs! The real trick though is to get your victim to sit on it in the first place, so hiding it under something is quite important. People very rarely sit on a whoopee cushion that is in plain sight, and when they do the joke is very weak because there is no element of surprise, just the funny sound of flatulence.
The problem of late though has been that my colleagues have become alert to the fact that I sneak around the office placing whoopee cushions on chairs, and that's where the self-inflating whoopee cushion comes in. I consider this to be an innovation that ranks right up there with the discovery of penicillin! The whole process of re-inflation is taken out of the equation and you are just left with the job of positioning the device in the first place.
If I had any complaints it is that you can't use any subtlety in filling this device with air so sometimes it is hard to position in such a way that it doesn't draw attention. And I suspect that the total volume of air expelled is slightly less than that of a traditional whoopee cushion so it simulates the effects of a large Mexican meal with refried baked beans, rather than a raging case of dysentery.
A good trick though, despite that fact that you don't have to blow it up, is to still moisten the outlet of the self inflating whoopee cushion because this improves the quality of flatulent simulation by anywhere between 15% and 20%.