I think it's some kind of auto-dialer but normally when I search for that kind of stuff someone will have reported the number somewhere. Cactus Bill may only be calling me.

I have answered and it's beeping but not the same pitch I remember with fax machines. I am tempted to cannibalize a fax modem from an old PC and see if I'm really getting faxed.

Oh and BDM, about a half hour ago I got a call from 000-0000. I assume it was my phone company but I would LOVE to find out how to make my number appear like that. No area code (we have 10 digit dialing) no prefix, it's totally bewildering.