Danny Outlaw of the Outlaw Design Blog has a nice Blog Action Day day post over at PSDtuts about 23 Awesome Examples of Design as a Force for Good.

While design is too often used as a means to persuade us to buy, buy and buy some more, it is less often but more importantly used as a means to communicate positive messages and encourage action. Here we showcase 23 examples where graphic design has been used not to sell us products we don’t need, but instead, to fight poverty.

Of course, we usually get a good dose from our friends over at http://osocio.org/ but this round up includes some interesting uses of clever advertising, messaging and design for good.  Check it (and some more PSD tutorials) here.