I came across this company while flicking through an old womens mag in the tea room at work. They sell sets of magnets, and they're used to create images on your fridge! I particularly like Elvis:
And here's what they look like on your fridge:
There are quite a few different colour packs to choose from (I prefer the grey-scale pack), and then you simply go onto their website, www.motifo.com and download instructions for the design you want! I'll be definitely buying a set once they come back in stock.