Has anybody heard of PinkDingo.com? It's a new way to make micro-donations to MWO (and any other charitable organization).
It's an easy way to make small donations either as a one-time gift or a recurring transaction. In addition, it has some facebook type features where you can track friends and form groups and challenges to work together for a cause.
Its worth checking out, and more importantly its an easy way to give to MWO.