Today I needed to receive a fax, and the free service at K7.net came in handy. From their website:

Sign up for K7, the world’s leading web-based unified messaging system that channels your free voicemail and fax messages directly to your e-mail. K7 Unified Messaging provides you with a free phone number. This number enables you to have your voicemail messages and faxes delivered directly to your computer. You also have the option to view and listen to your messages right here on the K7 Web site.

A quick and easy sign-up resulted in me receiving my own fax number within a matter of minutes.