Geeks Rule of Thumb
I am a fan of Hussman and Naked Capitalism referred to an article of his.
I love this expression:
Geek's Rule o' Thumb: When you have to fit a sixth-order polynomial to capture price history because exponential growth is too conservative, you're probably close to a peak.
Anyway, this post has a very good argument suggesting oil is peaked and bubbled and predicting $60 oil.