Inventions that would change the world Breathalizers for mobile phones. If you are pissed, it won't let you send text messages. And how about a night out shoulder cam? It would put an end to the age old question of "how did I get home last night?" Any more suggestions?
A device that can enable you to have a conversation with someone anywhere in the country by only using wires.
A magical contraption which costs about 1p that can turn dirty diseased water into fresh drinking water. An inexpensive pill which can cure aids. A spray that guarantees the success of crops. A machine which automatically adjusts your carbon footprint to match whatever you have been doing, sends the information to the rainforest so lots of people could plant the trees they have been felling for years. A remote control device which disarms every nuclear weapon in the world. A cure for cancer. A time machine. (this would change the world in many ways) Ice that doesn't melt. :groovy: