I've built a few simple things with it. Most recent is a small frame which under a car seat to support two cup holders on either side.
I'm trying to find some large diameter pipe which can hold drinking water. I've put a tall cal on my truck and its taking shape as a small RV and I was thinking of using large diameter pipe as water tanks mounted under the truck bed or even in the space between the inner and outer sheet metal of the bed. There are places I could fit a 6" pipe but all the larger pvc isn't supposed to be used for drinking water.