I don't know if there are any free dial up, and I am assuming you are in the states, so I really wouldn't know. However over here, you can often have a back up dial up connection which just costs the rate of a cheap rate local call, so if the connection goes down you can or you do something to the connection then you can still get access.
My problem is that I have long got rid of the modem in my PCI slot to free it up and create better airflow, but I can always whack it back in I guess