I've never been forwarded to a collection agency, but the public library has threatened to send a debt of $75 over for "lost books" they never sent me notices for.
Are you unable to pay anything on the debt because all of your income is already accounted for, or because you don't have any income? If you're making money and just not paying it, and if you ignore the collection agency, your creditor may try to get your income attached. If you can deal with it, just offer with your creditor to have your income attached at a realistic percentage (5-7%), and give them some assets as collateral.
Because of current market and economic conditions, things could go one of two ways; A) the creditor may be willing to bargain with you, because any immediate recovery could be better than no recovery (and if you manage to dick them around long enough, they'll have to write it off) B) They'll go after you with a vengeance because they need every last penny they can get.