I have to unavoidably make an amazon purchase and want to kick back money to the good guys -- but can't find any who has an affiliate set up!

So amazon has an associates system where anything bought through there has a certain percentage kicked back to the place that linked to them.
I'm having a hell of a time finding ones for doctors without borders, planned parenthood, etc... It's like they never heard of this!
The only ones that seem to come up in google are ones set up by bloggers to help them buy artisanal chocolate or something.

Does anyone know of a good guy who has one running? Thanks.