Robert, the American Collectors Association has a list of Forwarding Attorneys that specialize in collection of accounts.  Many attorneys are not interested in collection of accounts, but these guys are specialists at it.

They will usualy give you a flat rate to accept an account with a measured response.   For example, they will make a call and/or send a collection letter on your behalf.  If unsuccessful they will give you costs to file suit.  Usually, there is an up-front fee plus a percentage and results are not guaranteed but at least you know your costs going in and know that you are using someone experienced in collection law and local to the area where your debtor is situated. 

Sometimes it is a certain amount of satisfaction just to have a judgment granted.