In that past we've discussed countless uses of Twitter - beyond the obvious shameless self-promotion, which remains the microblogging platform's bread and butter. There's another side to Twitter, though, one that maybe deserves a lot more attention than it receives - philanthropy.

It should go without saying that the same power of connectivity that can bring celebrities like Ashton Kutcher millions of followers can be leveraged to improve awareness of the causes and issues that countless people around the world have pledged their time and money to solving.