eFax
Hi there. I have been using the free version of eFax for over 8 years. They gave me a Utah (!!!) number and I can receive faxes there. I do believe it also supports sending.
For receiving, you get an email notifying you that you have a fax, and it comes as a .BMP attachment. Neat.
I have never sent faxes using eFax, but if you have a standard dial-up modem, normally you will also have a Windows-configured "printer" that emulates a fax machine: you can send anything that you would normally print to a fax machine anywhere.
Check around their site
http://www.efax.com/en/intl/product/page/features and maybe the free version is still available. The pay version gives you features like local or toll-free numbers, etc.
I hope this helped.