The fax machine is going the way of the Teletype (TWX) machine. I my opinion, they will be gone in five years. Everyone has email these days and unless you are a high volume sender, scanning and attaching to an email is the way to go. I used that to get the documents to and from the bank when I refinanced my house a couple of months ago and they were used to doing it that way.

I got rid of my AT&T land line a couple of years ago and have my voice service by OOMA, a VO-IP phone service. The fax machine interfaces are so numerous and so nonstandard that it is essentially a waste of time to try to connect via a voice line on VOIP. The fax services that Ross mentions are another way.