Thanks for this Brian, a while ago I thought of something, exchanges may be able to do with the consent of users. There is so much dust (left over small change) from buys and sells. I wonder if there is something exchanges could do where users opt in to a decimal place position to say if coin X has 0.0003 on my account add it to a cumulative charity account on the exchange. Every 30 days the cumulative dust is then sent to a charity of choice.