You know... when I was a kid I loved the Digimon. Not the crazy franchise it turned into but the simple virtual pet that you raised and fought with others.
Its crazy to me that nobody has ever taken those and the Pikachu pedometer concept and used that for a virtual pet kind of idea where the very act of walking or running levels up your little dood that you can then battle with friends for fun times. Maybe even have the battles be events you don't witness but review when you get home. I know people already get really attached to their daily step counter "score" but imagine if there was a game based incentive to go for a walk or take your device on your hike etc. You could have a system where each day your steps become XP and while on your journey any streetpasses play out as quick battle events that when you get home you can see how many battles you've had and how you fared.
Maybe not an idea for the Pyra, but I keep hoping somebody will make something like this so I throw the idea out there any chance I get.
This could work (even for the Pyra). It is about time for these things to make a comeback so that the now adult kids that played with those can go give their money to some comapny and relive their childhood, along with the parents of kids who might like it. Start trying to sell the idea to toy companies.
As for the Pyra implementation, make a step counter, and games that make use of it, and just make those games playable online. It could be very cool if you make it more interactive (100 steps equals level 1 power up, 500 for lvl 2, 1000 for level 3 or whatever) and include it in a fighting game, or any game really. Even a stand alone Mario-like platformer with my power up idea would be cool. By including GPS tracking it could also look at distance traveled.
As for the original idea, I don't see why you would need to do any more than opt in by running it and turning BT on. It should include a name and message as a minumum, or maybe just a name "just in case". I can see the potential for bad, but also meeting/finding people that don't spend a lot of time talking about the Pyra with others online. I probably wouldn't use it, but discarding the idea because some of us are concerned about privacy is not the best solution. People can decide for themselves.
"But the more we are protected
The more we're trapped within"
-Peter Gabriel, "The Tower That Ate People"