At gadgetshop HQ, when the shutters come down and the reactor cools off after a hard day's product testing, we like nothing more than to toddle down to our local, The Faraday Cage, for a swift seven or eight. It's there that one of our all-time arguments had to be settled by a means so extraordinary that even we were stunned by it. After an age of mincing around and shilly-shallying, Geoff and Simon still couldn't decide who was going to pay for the last round. As most of us were drinking Appletiser, it was only going to come to £12.60, but, as they said, it's the principle of the thing. Quite so. So I sauntered back to HQ to collect the most devastating argument-ender known to man.

The Shocking Roulette is a randomiser designed to administer a shock to the finger of one of up to four participants. Who gets the potent but harmless jolt! It's impossible to predict. Simply insert your digit and bite your bottom lip as the clock ticks down with a menacing inevitability... then ZAP, the loser receiver a surge of electricity and has to pay the price. Pain is so close to pleasure, and as I enjoyed Simon's exquisite agony - as he received a zap then had to open his wallet - I reflected on the value of taking such a device with me everywhere to settle petty disputes.

Simon has never spoken to me again.