Anyone have experience with skax? skax.net it's a way to send faxes through skype. It gives you $1 worth of pages for free, but I don't know if it will work. I would try and test it out but don't have access to any fax machine to test it on.
You can get an free Efax account that lets you accept faxes online. If you want to send faxes online you have to upgrade for a fee though.