Actually the Langa list just had a thing on fax and dsl. This may be of some help
"Fax is a kind of machine-to-machine telephone call using analog signals over voice-phone lines; DSL is a kind of digital data network, unsuited for analog signals. But some DSL setups have a voice option (eg a place where you can plug in a standard telephone). In those setups, you may be able to plug a fax modem into that socket, and dial out normally. Or, if you can reach any other standard phone socket in your house from your PC, you can plug the fax modem there: You'll surf via the DSL (or cable) connection; but fax over your normal phone lines.
If you don't have a fax modem; they're incredibly cheap; often under $10:http://froogle.google.com/froogle?q=fax+mo...ab=wf&scoring=p
If that won't work for whatever reason, there are many web-based services that let you send faxes: These services accept your text or scanned photos or whatnot via the internet, handle the conversion to a fax image at their end, and then send the fax via their phone lines. There's usually a fee for this. Other services perform a second conversion, and send the fax as an email to your recipient; or store the fax on their system for the recipient to retrieve via their web browser. Some of these services are free, at least for low-volume faxing."
For more info on Langa List go to: http://www.langa.com/