The site branica.com has a tool that searches a term and its misspellings in eBay auctions.

   http://www.branica.com/misspelled-auction/

There are also some tips on how and why to exploit this.

   http://www.branica.com/misspelled-auction/misspelled-auction-tips.html

Maybe I should not post this.
It says "Shhh..don't tell anyone, just use our tool and start finding bargains instantly."