I have a question for you people who understand telephony. Lately I have been getting a fair number of fax calls to both my land line and cell. The fax machine at the other end tries at least 10 times before giving up. Would it be possible to built a box (ideally keychain sized) that I could hold up to the phone, press a button, and have it go through just enough of the handshake to decline the fax, and let the other fax machine know this number is not accepting faxes (tell it memory full, or not accepting or this is a voice line you moron). Whatever, just stop calling me?
Either that, or point me to an iPhone app that lets me enter numbers and have the phone decline them without even ringing (not even voicemail- pickup and hang up).