If they wanted people to carry the 3DS around, they should have made the system less clunky and more attractive to look at so the average consumer wouldn't feel embarrassed to be seen using one in public. Anyways, it could be as simple as limiting the functionality you get through a Streetpass on your smartphone versus one on a dedicated Nintendo handheld.



Maybe a smartphone Streetpass could give you some basic info on the other person's Mii, and tagging them again with your handheld would unlock their full profile. Just throwing some ideas out there.