Carrier type? fax or modem?

[m1t0s1s]

Anyone know of a web service where I can punch in a telephone number and the web site can guess what type of carrier noise it is? Eg, fax or modem?

If there isn't, to whomever wants to build this, it might be a cool way to get cool numbers!

[Decimalz]

I'm not aware of a web service that performs this. THough it is quite easy to tell the diference between modems and fax tones. Train your ears. Faxes make a specific tone and repeat it (waiting for the other fax modem to respond). Modems don't.