This is an interesting Firefox plugin I found..
Oil Standard is a web browser plug-in that converts all prices from U.S. Dollars into the equivalent value in barrels of crude oil.
When you load a web page, the script seamlessly inserts converted prices into the page. As the cost of oil fluctuates on the commodities exchange, prices rise and fall in real-time.
I just tried it with Amazon and its a pretty “fun” script. The price of a PSP is 3.97 barrels of oil while a new Macbook Pro will set you back 39.77 barrels. We should use this standard here in Kuwait, everyone could walk around paying in oil! [Link]