I was just thinking about this last night. I posted on the daily discussion thread a few minutes ago. Last night I attended a NY Mets baseball game at CitiField. On the walk back to the subways after the game, there is an informal marketplace where people looking pretty down on their luck were selling items like cans of beer, soft drinks, hats, shirts, etc. They held up handmade signs saying they accept venmo and zelle. Bitcoin seems like the perfect solution for them.

Of course, this is one anecdotal use case. For more comprehensive ideas regarding charities, check out the work of Alex Gladstein and Anita Posch.