Anyone ever heard of Charity Miles? Seems like an interesting concept, though I haven’t delved into it much or signed up yet.
According to various websites, including their own, you create an account, choose a listed charity, and then get ‘credit’ for every mile you bike, run or hike (as long as you’re carrying your smartphone with you). Those credits are then turned into real cash for your chosen charity. Doesn’t cost you anything but time, sponsors/marketing pays the bills. Seems interesting. Not listed on Charity Navigator.