I think the vast majority of these users are probably on their first smartphone. For example, Android is huge in African countries where families who've never owned a computer are starting to sign up for cheap 3G plans with cheap Android phones.
I bet there's a lot of waste, but I also bet that it's nothing compared to the waste from old American cars driving around and polluting. Think of what these new cheap smartphones mean for humanity - the ability for entire populations to pop on the internet that never have before, read wikipedia, etc. Surely that is worth the waste it is producing.
I wasn't really referring to the 'carbon footprint' if thats why you brought cars into it. I was more referring to things like PCBs and batteries, and the chemical processes used in refining these things. Toxic and harmful chemicals appearing in ecosystems they shouldn't... when things like cell phones don't get reprocessed properly.
There are plenty of toxic chemicals in car manufacturing. Hell, cars (particularly old ones) produce these toxic chemicals continuously while you drive them! Smart phones are a hell of a lot less toxic than cars.
As for the comparative benefits, we could argue until the cows come home - both products are insanely useful and life-changing - but if we simply declared them equally useful, that would make phones a better bargain due to the much smaller amounts of toxicity.
The good news is that services like gazelle, Amazon Buyback, eBay Instant Sale and Verizon Trade-in are making it more likely that old phones get sold and kept in use, instead of rotting in a drawer until they're tossed into the household waste.
I bet there's a lot of waste, but I also bet that it's nothing compared to the waste from old American cars driving around and polluting. Think of what these new cheap smartphones mean for humanity - the ability for entire populations to pop on the internet that never have before, read wikipedia, etc. Surely that is worth the waste it is producing.