Robert,

Didn't you mail him a check? If you don't still have the address you can get a little info on him when your check comes back. Take a look on the back of the check, it should have the name of his bank and his account number on it. Most banks have a coded account number where a portion of the account number designates a specific branch. Call the bank and find out what branch then check the phone book for the guy in that city.