I stumbled across a +45 minute podcast from the Royal Society of Arts yesterday which is highly entertaining, in a quantitative sort of way. The speaker that night was none other than Nassim Taleb, author of Fooled by Randomness and The Black Swan. It's a fantastic listen to, especially when he talks about something called "Black Swan positive."
Black Swan Events (BSE) are outlier events, events that you never dreamed of occurring but they do. Sometimes these are negative events where the outcome is very bad for you. An example that comes to mind was Enron, no one saw it coming and neither did Arthur Anderson. I bet the Anderson people never dreamed that this single event, from a single client, could cause them to go out of business.
The more interesting BSE's are the positive ones, these are the eureka type events which transform our daily lives into something better. An example that comes to mind is the discovery of penicillin, which was completely by accident!
According to Nassim, you should invest in companies that are BS positive because it limits your downside risk and leverages your upside. That's great advice but the trick is finding these companies and then paying a cheap price for them! :)