It is ingenious! You simply scratch off (using a coin, I assume) the places you have visited and over time you get a changing picture of your personal travel history. In addition to the classic world map, Scratch Map also offer a host of maps, from around the world, to fulfil all your cartographic scratching needs.
Thing is, I am now faced with a problem, as it is not Christmas for 10 months and my birthday falls at the end of December...*HINT HINT* :D
Happy travels, people! Get scratching!