I found these randomly on the internet quite some time ago, but just recently remembered about them and figured it could be an awesome idea for a bus, where space and water come at a premium.
now, I would imagine that it would only be good for hand washing after doing the deed. I wouldn't want toothpaste clogging up the lines in the toilet. I figure all other sink needs can be taken care of at the kitchen sink. This would open up so much needed space in the bus and would help save water. I just wanted to hear yalls thoughts on the subject.
http://www.sinkpositive.com/