Plastic water bottles used to build a school in the Philippines

I came across this video and it is an excellent example of how an intractable problem can be turned into a great resource.  In the Philippines, an ingenious group of people has built a school using disposable plastic water bottles as the building material.  Take a look at this great video:

Philippine School Made Out of Bottles

If you know of any other good uses for plastic bottles, please post a comment.