What3Words is a real world addressing system that gives every 3mx3m square on the planets surface 3 unique words, providing a unique and memorable phrase for anywhere in the world. This system allows for instant addressing to a very specific geographical location, which is very helpful for those in remote areas or areas where the existing addressing system just sucks.
Alongside the online mapping service (linked above), there are also related iPhone and Android applications that links in with the geographical capabilities of those devices on your mobile device to provide instant access to nearby addresses, as well as looking up addresses while on the move. This system has already begun revolutionising the world, with the Mongol Post, the state owned Mongolian postal system, adopting it as their official addressing system for the country.
Free!