So it's been nearly 10 days since Foursquare launched its social mobile game 'ground assault' into 50 more cities, including a bunch of European ones. But what I'd like to know is who's actually using it here in Europe? Because, you see, Europeans are already quite well served by location based mobile applications like Qype , the various localised versions of Yelp, and other startups like Rummble . And there are increasingly new kids on the block like Flook . What is clear however, is that only Foursquare and Gowalla (at least to my knowledge) have come up with this gaming approach to 'checking in' which has attracted so much interest from high profile blogs like TechCrunch and bloggers like Robert Scoble . The question is, which will scale and ultimate prove the winner? Because - at least in this instance - we have two distinct approaches to the issue of social, mobile and location.