Billionaire investor Warren Buffett looks for long-term return and considers railroads the future. "They don't need the government to build them new highways and airports," he said in an interview with USA Today last month. "They've already invested heavily in their infrastructure and technology, and they plan to invest more to keep up with the growing demand. They're the only mode of freight transportation that can handle growth. What's not to like about that?" In Buffett's most recent letter to shareholders, http://www.scribd.com/doc/27563128/Berkshire-Hathaway-Annual-Report he explains his and partner Charlie Munger's business tactics at Berkshire Hathaway ( BRK.B). "Just because Charlie and I can clearly see dramatic growth ahead for an industry does not mean we can judge what its profit margins and returns on capital will be as a host of competitors battle for supremacy. At Berkshire, we will stick with businesses whose profit picture for decades to come seems reasonably predictable. Even then, we will make plenty of mistakes." However, he doesn't want to discourage being aggressive when the market permits. "Big opportunities come infrequently. When it's raining gold, reach for a bucket, not a thimble."