Havent tried that one yet! Minus saying more individuals back bitcoin than USD and too many people have jobs based on bit coin dev, mining, invested etc, for it to suddenly crash to $0 in a day like it could a few months ago, albeit it still can, more people would resist the price drop and it would surge in price again if that DID happen.
Bitcoin is now bigger than 20 or so national currencies. The way I see Bitcoin being backed by the miners is that should one stop mining another person or two or three will replace them. Just like if a company stopped mining for gold another would soon replace it. Look at Bitcoin over a 10 year period and not a 10 week or month period. The future is brighter for more than others and I know where I am laying my bets. You should watch Tuur's speech at the Bitcoin conference
http://www.youtube.com/watch?v=K7LQu-eIOO0 I had a Skype chat with him a few days ago and he is very knowledgeable and looks at the bigger picture (Just how I wish everyone would)