Check out this site. And, after clicking the button, be sure to check the tabs at the top of the page.
And try Goodsearch. Every time you use the search engine, a penny is donated to your favorite cause. And, if you use the site to go to your favorite stores [listed below the search slot] they will give a percentage of your purchase price to your cause.
I just changed my book-buying destination. I discovered that Amazon gives 1.5% and Barnes & Noble gives 3%. Who knew?
Demeur noted that there's another one out there: free rice.com. There are several quizzes you can take. Each correct answer gets 10 grains of rice sent to the hungry. To date they've sent tons of rice around the world. And it's free for you. Paid for by sponsors.
So, you play a game, have fun and help people who need it. What could be better?
And are you a Facebooker?
There's a site there called Save The Planet. Another game site, there are dozens to choose from. Play, earn points and L$ [lunch money] and donate it to your favorite cause [again, several to choose from]. Sponsors then turn your play money into the real thing and give to the cause of your choice. You even get to see just how many ounces of CO2 you're pulling out of the atmosphere, how many grains of rice you're sending to the hungry, how many square inches of blanket you're giving to the homeless or square feet of rainforest you're saving.
So, if you enjoy playing games anyhow, why not do it and make a difference?