The Cisco IP phones (7960 and VIP 400) are IP only. They also will not work "stand-alone, " or over the Internet. They *may* work over a private WAN, but Cisco VoIP is still pretty sensitive to latency. A careful site-survey should be conducted for end-to-end qualification of the network should be done before purchasing or installing a VoIP system.
On the "plus" side, they do run XML, so you can customize your menus, display Web-based information (if programmed to do so), or display other information from a server other than the Call Manager. I believe one of the airlines is (or will be) putting Cisco VoIP phones in their lounges, so that member/customers can check their flight schedules (on the phone display) while conducting other business.
FWIW
Scott