I'm not talking about the less fortunate here, but adapting the Turk idea to something else half-baked.
I could categorise 50 images in 2-3 minutes. It'd take me 1-2 minutes to get out my wallet, get the right credit card and enter the info if I were to pay manually.
I ran the idea past two employees (neither homeless...) who both seemed to think they'd consider a quick spot of Turking in exchange for a digital good.