http://www.thetakeaway.org/2008/apr/23/betting-on-the-oil-markets/ http://www.podtrac.com/pts/redirect.mp3/audio.wnyc.org/takeaway/takeaway042308a.mp3 Betting on the oil markets http://www.thetakeaway.org/2008/apr/23/betting-on-the-oil-markets/ true 5882 segment The last time that we saw gas prices rising this quickly was in the 1970s, when Americans responded by cutting their gas use by 30 percent. Lisa Margonelli, author of "Oil on the Brain: Adventures from Pump to Pipeline," says the high price of oil is, in part, driven by one group of people that surp