I think this is what's happening...

There's going to be helmets in 50 years. The space kind with filtered vents. For now people are just walking around with facemasks and iPods but you can see where it`s headed.
My girlfriend thinks I`m crazy when I talk about the future in Japan, but I`m sure this time. It won't be everywhere, but for those people on the edge of technologies it's the next thing.
Just like with the bottled water people, the helmet companies will play on the fears of the healthy. If it`s not air pollution then it'll be airborne sicknesses and when the advertising is done people will wonder how they ever lived so long with such a filthy habit as breathing air.
I imagine the high-end versions. The slick eagle-head kind of helmets. The kind with temperature controls, speakers and visors that dim on the inside to display movies. The artists will have theirs too with cameras that intuit retinal focus for zoom and blinks for snapping pictures handsfree. Moms in supermarkets will buy cereal but only if it's highlighted in the visor. Afterall, the helmets in 50 years will be able to scan the RFID Chips in every package and compare its nutritional values and costs against an individuals Shopping Profile. Recommended lists can be downloaded for strength trainers, dieters or people trying to budget.
And nothing won't be packaged and tagged. Food production is completely decentralized from cities in 50 years and everything is shipped in airtight. Apples have plastic skins. When you checkout you just walk out and a pylon will scan your cart, or anything in your pockets, and charge your card. There is no shoplifting in 50 years. No cashiers.
The whole world will be an inch from our face.