Greetings from sunny Houston. The hotels are overrun with basketball fans donning the colors of Duke, Baylor, and other colleges playing basketball here tonight. But the NCAA tournament isn't the competition that brought DISCOVER deep in the heart of Texas. We're here for the Shell Eco-marathon Americas. All weekend long in downtown Houston, students from 29 universities and 9 high schools will he going head-to-head with their prototype ultra-high mileage vehicles. Most of the 50 vehicles are powered by combustion engines, but a smattering of vehicles running on ethanol, hydrogen fuel cells, solar, and petroleum gas have come down to challenge the traditional engine. Check Discoblog over the weekend, as we'll be continually updating on the wild cars and their brilliant young designers. Official competition runs Saturday and Sunday. However, given that winners of past eco-marathons have reached efficiencies in the thousands of miles per gallon, these vehicles might just keep on going.