I was talking to Ged from eCalne last week about how people are making money by searching sites like ebay and craigslist for typo's. Buying the located items cheaper as the main audience for the items has not seen them because of the typo, reselling the item on ebay without the typo to make a profit some of the time the items are even resisted with correct spelling before the Typo Squatter even has the item. Here are a few links to help you both find common typos and avoid them in your own auctions and online sales. Good luck

Typobuddy.com - Can help you find commond typos on ebay and craigslist
Typo Squatting - Making money from a domain name typo, More info Here