Build a Toilet; £30

This is the second lavatorially oriented item on my list - it's not something that comes up in conversation very often, for obvious reasons, but erecting this corrugated iron toilet could make a big contribution to improving health and hygiene in (for example) a refugee camp.
Cholera and typhoid thrive where there is inadequate sanitary provision. Build one of these and help make sure they don't!

[ from Oxfam Unwrapped, www.oxfamunwrapped.com ]