A billboard in Sweden has taken advertising to a whole new, high tech level by allowing nearby iPhone users to interact directly with the board using their phones.
McDonalds has set up the giant billboard so that people with an iPhone can play a form of pong on the big screen. Whoever 'wins' in a game against the billboard then receives a coupon to get a free McDonalds meal.
So many different sites and apps are offering coupons at the moment, so it's nice to see a brand making people work for it a little and offering customers something a little different. At the same time the barrier to entry isn't too high (assuming you have an iPhone that is) and I can imagine a lot of people jumping on board just for the novelty at first!