Just what you need - a way to waste time while doing good - so you are torn between the guilt of knowing you should be doing something else, and the guilt of not doing a good thing.
freerice.com donates rice while you idle away your time on their site, paid for by sponsors whose ads you see while playing. You answer vocabulary questions and rice is donated for every right answer you get. Quick - what's the meaning of "entomophilous"? Blow this and a child starves! (Pollinated by insects, btw. Now you know.)
It's a clever idea, and has spawned a couple of imitators - FreeKibble.com and FreeKibbleKat.com which donates food to shelters, again, for the priviledge of exposing eyeballs to ads. FreeRice is particularly sticky (the site, which means that you hang around it, as it gives you a never-ending stream of questions, of increasing difficulty. The other two have one question per day, so while you can visit every day, there is little incentive to stick around.
So there you go, more ways to waste your precious time, when you could be beading. Now, if they just had a website that donated seconds to needy beaders . . . .