Angry protesters in Libya may make for annoyed drivers in the U.S. The price of a barrel of crude oil hit $100 a barrel Tuesday, its highest point since October 2008. The spike is a result of concerns that tension in Libya, a major oil producer, could slash the world supply of crude. Production there has already been disrupted, and leader Muammar Gaddafi has reportedly threatened to blow up pipelines. And protests could spread to other oil producers in the Middle East. Oil futures spiked despite promises from other OPEC members that they’d increase production to make up for the lost Libyan oil, although the price has now fallen to just below $100. The effect on prices at the pump is not clear.