When a popular clickbank product is about to be released I check to see if there are common misspellings of the domain name and if there is, I'll buy it (if available) and do a url redirect with my affiliate link.
The way I check the likelihood of a misspelled word is using Google's keyword tool.
An example of this is forexconqueror.com. Many people misspelled it as forexconquerer.com. I made a few quick sales and some easy profit
