Here are my quarter baked ideas, waiting for me to flesh them out:
Preheat air for a biomass gasifiyer, using a heat exchanger between the intake air and generated gas.
Cross a dustmop with a cotton gin and a bissel floor sweeper.
Flat spiral CFL for floodlights
Compressed air hover furniture (or hover dolly)
"Failed Scan Count" If credic car scanners counted the number of failed scans before a successful scan, & the card issuer collected that info, they could detect worn out cards, & issue replacements.
"Bipartisan campaign signs" To reduce vandalism of political campaign signs, make signs which support both candidates.
RGB Flash for cellular microscopy (less heat, less damage to cells being photographed)
Extra slow escalators (along side stairs), to encourage people to take the stairs (and thus get some exercise), while still allowing them to ride the escalator if necessary.
Use & discard LED laser bullets -- LEDs/SEDs.
Thermoacoustic Turbine Engine
Half a cup of coffee - semicircular curved ceramic portion, flat glass portion.
Tow-behind biochar kiln, to be attached to combine harvester. Crop wastes which would normally be shredded and spread, to rot on the field, would instead be charred (and quenched) first, then spread on the field.
Supply oven for cooking food with pure oxygen, instead of regular air.
Cyclone separator for dryer lint removal
Collar lifter, allows warm air to escape shirt (for summer use)
Solar Powered Clock (PV & capacitor, or steam & weights)
Enhanced extraction from grape must by RO & water circulation. Result: less water in the liquid to be fermented.
Carousel Store signage -- aisle numbers, and lists of what's in each store aisle, go all the way around each cylindrical sign. This allows more text in a small area.
"Forever" respirator -- uses PSA gas separation to remove one specific chemical from a stream of air from the atmosphere. The chemical separated is discarded/destroyed/stored, the rest of the air is breathed.
Musak with memory. A pay radio station encrypts and transmits it's music, the reciever decrypts and stores it internally. If a thunderstorm or other EM disturbance disrupts the signal, music is played from the appropriate segment of the recording.
Small, cheap timer/alarm, with multi-week snooze button. Stick onto the HVAC air filter, etc..
Turntable coffee stirrer. Put coffee in cup on turntable, spin until coffee almost overtops sides of cup, reverse direction of spin; repeat as desired.
Cyclonic filter for household air purifier.
E-Ink children's blocks.
Remote control water heater thermostat -- this on-demand heater produces hot water that's no hotter than the hottest faucet/appliance which is using hot water, by asking each faucet/whatever what temperature is desired.
Vibration canceling motion sensor. This allows a fan to turn on if there's motion in the room, and more importantly, turn off when it's the only thing moving in the room.
Laminate newspaper as construction material -- recycled car?
Custom packed assortment
Reduce invasive species in shipping -- sterilize the ballast water.
Lego physcis engine - 2D & 3D versions
Milk in glass bottles, with empty/full exchange in supermarket. Similar to delivery, minus delivery fee.
Multi-company glass bottle size & shape standardization, to allow sterilization & reuse, rather than crushing & recycling.
Capsicum pepper pill -- as a "chill pill" to increase blood flow to skin, and make one cooler (summer use).
soap foam filled torus heat engine
Pop rock coffee sweetener -- you can hear when the sugar's dissolved.
Gradual start / stop for economic incentive programs -- if the money tapers off, instead of being cut off, there won't be quite so much of a rush as the deadline approaches, so the computer server's won't be inundated.
Aerodynamic homes lose less heat.
mono-symptom cold medicine system -- a set of compatible medicines, each of which treats a few disease symptoms. Each one has fewer side effects than a "treats it all" medicine.
Continuously variable home heating/cooling. Not just off/on, nor even off/low/high, but any setting at all between off and high. Possibly combined with a PID controller or adaptive system, to maintain home temperature exactly.
Home hydronic fridge/freezer, with a water cooled, not air cooled, refrigerant condenser. Waste heat is either distributed through house or disposed of outside (or disposed of into a geothermal loop).
Adaptive learning automatic door. Opens when people are entering/leaving, not merely walking across it's line of site. Opens just early enough for the doors to be out of the way of the person walking through -- if someone is moving slowly, they open when he gets close; if he's moving quickly, they open earlier.
Revolving storm door -- swap screens for glass in the summer.
Variable speed revolving door panels. This allows a four panel door to have a wider entrance and exit, or allows a three panel door.
Oversized revolving door, with appropriate sensors, motors, etc., to allow shopping carts through.