I appreciated the whole post, but I felt you left out the one thing I wish all the many conferences I attend would aim for: biodegradable badges. I don't keep my badges and don't need to. The volume of detritus ("schwag") that gets handed out, not to mention the reams of paper, barrels of ink, etc., which are wasted to print literature that could easily have been emailed or posted for download, makes me want to conserve the Earth a bit more. I come for the people and the content of the talks, not the badges. I'm sentimental about other things. Meanwhile, I have to throw away or recycle the junk, standard plastic sleeve, printed nametag insert and printed lanyard (that I'll never wear again), and then the conference lapel pins. As a legislator I have accumulated enough lapel pins to open up a shop.

Give me a badge that does everything you mention but that can be recycled, reused or thrown away with a net-positive environmental impact.