Until everybody has an electronic signature, the fax will still be useful in business because it provides a fast and inexpensive hard copy when an "original" signature is required. Today's plain paper business faxes all use electro-optical (laser) printing, so the output is usually as clean as the original.

And sometimes, the rules require its use. Every pharmacy I support has a fax machine so doctors can fax in prescriptions. They will maintain those faxes in place until the FDA finally says that an electronic copy is just as good as a hard copy or until every medical practice adopts e-fax.

I'm not holding my breath for that day.