Once upon a time, long before Skype, when a spellchecker would insist on replacing VoIP with "void" and cell phones were the size of a brick, there was a company called Cidco that created a home phone with a browser and called it iPhone. Some got excited, others hated it. It was a cool idea, though. Imagine how much easier it would be to set up your voicemail, do call-forwarding and - gasp - navigate the airline ticket-reservation systems. Would work well for getting ads and coupons from the local stores. Looks like you still can get one of those in New Zealand. And here Jacob Nielsen discusses usability issues around data phones (1997).