I have one pair of copper wires coming into the house. They do telephone, broadband, and fax. I just send faxes on the normal voice line, using WinFax Pro on the PC. If they aren't generated on the PC, I scan them in via Paint Shop Pro.
On the one occasion in about three years that I need to receive a fax, I tell the PC that it's a fax machine, and it answers the phone and does the fax bit.
I believe there are "Internet Fax" providers, who will receive the fax on your behalf and send it to your PC. You then print it off as a JPEG.