It's a tricky question, and I think it should have a whole website due to the actual importance of the question.
The website, if created, would display things like this:
-$1 pays for one two billionth of B-2 Spirit plane
-$1 also pays for one tree being planted (according to #teamtrees)
-$1 can buy anything from the dollar tree
-$1 can buy one 20,000th of a honda civic
-of course this list is far from finished
My main question is: how can a dollar be spent the most efficiently , as far as donating or investing, so society could progress as fast as possible.
Also, has anyone already found a website that does this? I couldn't find one.