Now the GPS dataset is something I had not considered. A good point! Thanks.

it may turn out to be the biggest gamification success until now.

it's amazing how much it even changes my daily routine and how I walk around....no longer is it the fastest route; it's now the route where I can hit the most portals haha

Yeah, it's been pretty successful at driving additional walking for me. I'd been meaning to get more exercise, but finding difficulty getting motivated -- now I pretty routinely walk a couple extra miles per day.