Does Taipei offer anything like this?
Not sure exactely what you want, but Chung-Hwa telecom does offer call waiting and call forwarding. I have call waiting and I don’t think I pay any extra for it, call fowarding however costs you. I once fowarded my land line calls to my cell phone, that wasn’t a good move as I ended getting stuck paying cell phone rates for those calls, I thought it would be free as the person was calling me… stupid…