I do exactly this today, using Phone.com as my home VoIP provider. One "universal" number rings both my cell and the VoIP land line determined by my travel sche

I do exactly this today, using Phone.com as my home VoIP provider. One "universal" number rings both my cell and the VoIP land line determined by my travel schedule. Not on my whitelist? A prompt asks the caller to dial 7. No robocall has gotten through since. Of course if this were widely available for people who can't write five lines of code, it would be defeated. For HN readers, some of whom scripted checking into Continental flights right at the 24 hour window to game the upgrade list, this is child's play that works.