Four years ago I wrote about a way to encode the latitude and longitude of any point on the Earth's surface to 10m of accuracy with a 10 character code. Apart from a modification to the way the check digit is calculated, the code remains unchanged.

The idea is this: instead of giving people addresses, or coordinates, you can give them something like a post code for any point on the Earth's surface. This can then be entered into a GPS device and decoded. Thus a business can provide its 10:10 code and know that people will be able to find it.