On the way home from work, you can tell my dad was driving, because radio 4 was on - and I never thought that I'd ever say this...but...it was actually quite good! They were doing a piece on money and the history of it, how initially, people bargained with gold, which led to gold standard.
The only reason paper money became so popular was because it was a universal consensus that it was valuable. They made the very interesting point, that if everyone took a bit less interested in cold hard cash then it would be less valuable.
If we did in fact, start trading things with an actual value such as food, shelter, clothes etc then cash would be worthless and we, as a society would be richer. Whether they mean morally, intellectually or physically rich is unclear.
It is an interesting point though, maybe one day it'll happen... Who knows...