Landshare is a UK website that aims to bring together people who have a passion for home-grown food. The site is designed to connect people with a bit of spare land with those who want to grow food but don't have anywhere to do it.
Landshare uses Google Maps to show the locations of plots of land that people are prepared to share and the locations of those who are looking for some land to grow their own vegetables. It is possible to search the map by address or postcode. It is also possible to refine the results to just show those looking for land or those who have land to share.
If you are a map developer and you think you can produce something as good as Landshare then you should enter the latest GeoVation Challenge. Enter the GeoVation Challenge "How can Britain feed itself - sustainably?" and you could win yourself a slice of £25,000 to help implement your idea.