These Fortune 500 stocks offered some of the best returns to shareholders for 2007. Riding the ethanol boom with Mosaic, corn farmers increased their acreage by 24% from 2006 to 2007. That meant a surge in sales for the Plymouth, Minn., company, which is the world's second-largest fertilizer producer. Prices of its two main products -- potash and di-ammonium phosphate -- have doubled and quadrupled, respectively, since early 2007.
