I always got a kick out of the social GPS application Waze. Their last contest had people running around the country finding fruit to drive over in their app. Their latest one revolves around the World Cup and actually looks nice and thought out.
Users in each country compete to “eat” the most soccer/footballs in the app. There will be a few rounds and countries based on their top 11 munchers will be whittled down to 16 and then 4. Out of those 4 they will choose a winning country. They will then raffle off 3 free iPads to users in the winning country based on a proportion of how many soccer/footballs you consume.
Kind of an interesting idea though I fear it might distract drivers from the road. What do you think? Will you participate?