According to the Clean The World campaign, American hotels discard millions of pounds of soap and shampoo every day, cloggging up landfills and contaminating water sources.

Meanwhile, millions of lives around the world are lost to disease because of a lack of simple handwashing facilities. Seems like all you've got to do is stop throwing away the soap, and give it to the people who need it. Simple. That's what the campaign aims to do.

It only seems to be active in North America at the moment. But you can do your bit by staying at hotels which support it; or by asking the hotel in which you're staying why it doesn't support it.