Today’s invention is an alternative to a conventional keypad.

The teeth of a metal zip, located in one’s bag or clothing, are wired electrically so that when the keeper travels to a certain position (connecting a subset of the zip’s teeth), this is recorded by a sensor attached to eg a mobile phone or even an ATM.

The zip would thus be a representation of the number line (with 0 at one end, 9 at the other and the rest of the numerals arrayed at equal intervals). The keeper need only be paused close to each numerical position for that number to be recorded.

It may be arranged that the keeper position generates an audible tone and so certain telephone numbers would then develop a cachet, based on their acting as recognisable tunes.

In this way, conventional keypads can be dispensed with (saving bulk and cost) and security enhanced -since shoulder surfing can be made almost impossible.

Today’s invention is a way to provide relatively simple gearing for a bicycle.

Both front and rear sprocket wheels have arms which are extensible, being driven outwards (or inwards) by eg pressurised hydraulic fluid. Continuous gear changing could be achieved by electrical switching of two hub-mounted pumps.

At the ends of the arms, roller bearings engage with the chain (more arms might be required than shown, for the smoothest possible operation).

A light, springloaded idler wheel is used to keep the chain in tension and avoid slippage.

It might also be possible to have a system tuned so that the arm lengths are individually optimised in realtime for a given rider, on a given gradient and as a function of pedal position.

Soldiers operating in dusty conditions are often surrounded in a localised cloud when they fire their weapons.

This is caused by the various spherical shockwaves created as high velocity rounds leave a weapon and which then brush across the ground and generate clouds of dirt. The effects are that a camouflaged individual can be spotted by the puffs of dust he is stirring up and also that his own view of the enemy is obscured.

Today’s invention is a camouflaged, foil-lined sleeping bag which is placed lengthways in front of foxhole after filling with earth.

This acts to contain, refract and disperse the lower half of a shockwave before it can interact with dust on the ground near the the firing emplacement. It also acts as a barrier through which any ground dust will have trouble rising.

If you want to go hot air ballooning, it requires the transport of large quantities of gas in cylinders, which is pretty energy-inefficient and also dangerous.

Today’s invention is a way to balloon in hot countries.

A large, plastic fresnel lens focusses the sun onto a ceramic tile of the type used on the space shuttle. This will transfer a large amount of heat to the surrounding airflow, without significantly heating the basket to which it’s attached.

The air in the envelope is thus gradually heated enough to allow takeoff to occur (with a small gas bottle and burner on hand in case of long periods of overcast weather).

I watched in horror as a favourite DVD froze the other evening in mid-scene. Having tried all the usual restarts and disc cleaners, it occurred to me that it would be great if one could just download a patch of data to allow the player to bypass the damaged area.

Only very small sections would ever be downloadable so this would not be a way to get hold of a whole movie, but it would allow realtime repairs to a damaged disk.

Today’s invention takes this a stage further. By arranging that each new disc surface be deliberately scratched in the factory (in an invisible, but unique pattern).

A viewer could then only see the digital content if their machine requested and downloaded several patches which were unique to the particular disc in question.

Only one set of such patches could be downloaded per disc, making copying a disc, without access to the patch server, impossible (and futile).

Bill sticking must be a pretty frustrating job.

No sooner have they finished pasting up the latest set of coloured paper squares than they have to scrape some off and start all over again.

Today’s invention is a robot printer for such advert spaces. Each large billboard would be fitted with a small printer suspended, in a weatherproof case, from a vertical arm. This would attached to a cart running on a track along the top edge of the billboard frame.

The printer would be equipped with a wireless receiver which would allow it to be driven by motors to precise locations (just like a flatbed printer turned through 90 deg into a vertical plane).

Fed with waterproof paint/ink from reservoirs behind the board, it would be capable of repainting a huge advert in minutes and thus providing a cost-effective alternative to the electronic adverts which are supposedly on the rise but which are enormously costly and unreliable.

Credit card fraud costs us all money (since the banks aren’t about to take any responsibility for it -or indeed, it seems, for anything).

Today’s invention is a simple ‘honeytrap’ system to further frustrate credit card criminals.

Every time I get a new card, I’m supplied with say four others, identical except for a small numerical variation in the identifying codes. These I carry with me so that they all develop a similar level of wear within my wallet.

If said wallet is stolen, the thieves have a four in five chance of having their illegal transaction fail, alert a central system to the IP address being used and immediately disable the real card.