Device employed for exterminating rats, mice and other animals (patent number: US 883611) The pitch: Rather than killing the rat this device attaches a bell around the animal's neck when caught in the trap. "The thus bedecked animal is not caught or confined in any manner whatever but is free to return to its bole and colony. The 'bellrat', as it may be termed, then in seeking its burrow or colony announces his coming by the sounds emitted by the bells, thereby frightening the other rats and causing them to flee, thus practically exterminating them in a sure and economical manner."

Application: The scratching noise under my floorboards is gone. It's been drowned out by bells.

Combined bird trap and cat feeder (patent number:

US 4150505) The pitch: "A bird trap and cat feeder for catching birds and feeding the birds to a cat." In other words, little birdies alight on trick perch, which collapses and traps them until the cat chooses to eat them.

Application: Like something Pol Pot would have had in his garden.

Motorised ice-cream cone (patent number: US 5971829) The pitch: "Eating receptacle for supporting, rotating and sculpting a portion of ice cream or similarly malleable food while it is being consumed."

Application: For those long hot summer days when you can scarcely dredge up the energy to poke your tongue out, not to mind actually rotate the cone.

Subliminal recording device (patent number: US 6940432) The pitch: A teddy bear with a recording device inside that activates at night to "provide an ideal medium for affirmation, self-hypnotic suggestion or subliminal instruction".

Application: None, unless you are planning to raise your child to be an evil dictator.

Male chastity belt (patent number: US 6736142) The pitch: "Protective tube and harness for the masculine member. The tube continues with a hinge with a hole at their end. The member is placed into the said tube, fixed with adhesive tape to the hinge?" Actually let's just stop there.

Application: Painful, by the sound of things.

Passenger control system during a plane flying (patent number: US 6970105) The pitch: Basically, it amounts to forcing everyone on board to wear a dog collar related to your seat number. Misbehave or attempt to hijack the plane and a syringe in the collar will be activated by staff to take you down with sedatives.

Application: Most passengers would prefer to be unconscious flying, and we know most air stewards would prefer it that way too; this one just might be a runner.