Portfolio losses got you down? That's understandable. The dramatic 2008 market drop-off caused the S&P 500 Index to tumble 37%, wiping out more than $4 trillion in workers' retirement plan savings alone. Continued stock market and housing value declines in the first quarter of 2009 resulted in an additional loss of $1.3 trillion of savings for Americans.

If you lost money, you're not alone, but at least you can put some blame on the market. Major errors of judgment have cost some of the world's richest people more than just a pretty penny - and these are people who have a lot to lose. Console yourself with these famous financial flops.

1. Two Rocks and a (Could Have Been) $17 Billion Family Legacy

In 1883, Dr. William Howey went to check on crews building the Canadian Pacific Railway. While searching for a lost worker, he found some interesting copper-colored rocks and pocketed them. Upon returning home he sent them to the director of the Geological Survey of Canada. The verdict? The stones were deemed worthless, and Howey threw them away.

A contractor picked them up, and a year later decided to check out the site where they were found. It turned out those "rocks" were copper and the contractor - Thomas Murray - had discovered one of the world's largest copper deposit, producing millions of dollars of ore. When it was discovered the ore contained high levels of highly sought-after nickel, the deposit was named the International Nickel Company of Canada, and went on to become the second-largest producer of nickel worldwide. In 2006, Vale (NYSE: VALE) (previously CVRD) bought the company (named INCO) for $17 billion. Talk about a