The invention should be physically conceivable. A tissue-paper chassis couldn't even hold itself up, let alone try to serve as a chassis. Supernova-powered flashlights don't make any sense at all.
The invention should attempt to improve on something or serve a purpose. A mesh umbrella would allow people to see the sky, but a mesh raincoat would be as useless as a concrete parachute.
The invention is not an oxymoron. Some items, such as Jumbo Shrimp, Military Intelligence, and Politicians that tell the truth, fit more in the Canonical List of Oxymorons.
Some inventions may seen useless at first but are actually quite useful. They are not part of the main list. Some examples of these are:
7-day or 10-day Federal Express Service 100% Goose Down T-Shirts 100% recyclable environmentally safe chainsaw ABS for Bicycle AC adapter for electric cars AC adapter for solar calculators Air Bag for Aircrafts All-terrain roller blades Anemometer waterproof to 200 Ft Armpit-Scent Deodorant Asprin Flavoured Non-asprin painkillers Asprin Flavored Gum Battery powered battery charger. Battery powered nail clipper. Battery powered nose hair clipper Battery powered straw Bifocal binoculars Black Highlighter Braille Drive-thru ATM's Braille Driver's Manual Braille Encoded Cam-corder Brake oil Broom with bent handle Bubble-less Champagne Cabin pressure system for Cessna 150 Camouflage Billboards Cast iron toilet paper (durable) Cast iron wire Cat flap for the fridge. Centre-zero speedometer (useful for reverse) Cereal enriched with optical-fiber Checkered paint. Clapper-Operated Door Locks Clapper-Operated Stage lights Clear Correction Fluid Clear High-lighter Coin-Operated ATM's Compact Disc Rewinder Compact Limo Computer Mouse Trap Cord-less Extension Cords Cord-less Pay Phone Cord-less Plumb Line Cord-less Wire Decaffeinated Vivarin Dehydrated Water De-ionized Plasma Deuterium (D2O) filter for kitchen faucet Diet Celery Dim/Tinted High-Beams Dolphin-Free Whaler Harpoons Downhill Stair-Master Dry Towelettes Edible condoms Ejector Basket for Hot Air Balloons Elastic accessories for "No Nonsense" Bra Electric banana straightener Electric kazoo Electricity Powered Generator Fake Faux Pearl Necklace Fake Rhinestones Fireproof Matches Fizzy milk Flashbulb tester Foam rubber toothpicks for sensitive teeth Frictionless Sandpaper Frowning Smileys Furry Toiletpaper Gasoline Powered Air Freshener Gasoline Powered Calculator Gasoline Powered Exercise Bike Gasoline Powered Hearing Aid Glow-in-the-dark India Ink Glow-in-the-dark Soap Glow-in-the-dark Sundial Glow-in-the-dark Sunglasses Glow-in-the-dark Suntan Lotion Hair Dryer, Underwater Hair Dryer, Weatherproof Hand Powered Chainsaw Heated Refrigerator Heavy Duty Bath Soap with Bleach Helium Paperweights Humane Ant Traps and Roach Motels |
Humane fish hooks Humane Torture Racks Ice skate sandals Imitation Cubic Zirconia Imitation Puppets Impact-Triggered Parachute Inflatable Anchor Inflatable Dart board for Camping Insoluble Suppositories Instant Dry Dry-Skin lotion Left-handed Bacon Stretcher. Lighter powered Car Battery Charger Liver flavored Lollipops Low Salt Brine Low-calorie Power Bar Matte finish floor wax Mesh Condom Mesh Umbrella Monitor-wristrest computer combo Motorcycle Air Bag Motorcycle Air Conditioner Motorcycle Ashtrays Motorcycle Cup Holders Motorcycle Windshield Wipers Motorcycle Seat Belts Nintendo Monitors, Printers No-fault earthquake insurance No grit sandpaper Non-Alcoholic Everclear Non-drip cooking oil Non-toxic Chemical Weapons Nuclear Powered Radiation Detector One way round trip tickets Open-tipped condoms Polite Car Alarm (that reads Miranda rights in English) Pollution-free detergent Portable Dishwasher Precision zero volt reference Press-On Nail Top computer (Intel(TM) Inside!) Radar Detector for Runners/Joggers Remote Controlled Exercise Bike Remote Controlled Remote Control Re-usable tampon (yuck!) Screen Doors for Airplanes Screen Doors for Space Shuttle Screen Doors for Submarines Second-hand fireworks. See-through Blinds See-through yashmaks. Serial bus hard drive Shopping Carts for Homeless Silly Putty! Snow Tires for Bicycle Solar Powered Flashlight Solar Powered Pacemaker Solar Powered Tanning Bed Solar Powered Torch (no batteries) Soundproof Speakers Steel-Belted Radial rubber bands Strap-on portable chairs Sugar Coated Toothpaste Superconducting insulator Super-glue Post-it Notes Toasted Popsicles Toupee/Wig with a chinstrap Training Wheels for Sports Cars Unbreakable Pinata Umbrellas with Sun Roofs Unscented Perfume Velvet Raincoats Virtual reality bathing/showering Virtual reality fishing Water: freeze-dried, instant, diet Waterproof Powder Waterproof Sponge Waterproof Tampons Waterproof Tea Bags Waterproof Toilet Paper Waterproof Towel Wax Flowers for Outdoor use Windscreen-wiper warning light Wind-up radio or tv World's Largest Microchip XL bicycle clips, for cycling in shorts |