Folks visiting China (for example) can benefit from using a VPN service to allow otherwise prohibited access to Internet resources. Cornell VPN is not the right tool for this,, but there are many other commercial VPN services available to meet this need.
Cornell's VPN service is designed to facilitate access to Cornell-based resources. It is not a generic VPN service. Specifically, Cornell's VPN is a "split horizon" service so if you are off-campus and are accessing a Cornell resource, the VPN is invoked. But if you are using an off-campus service (Facebook, Box.net, Google, etc.), it does not go through Cornell's VPN:
http://www.it.cornell.edu/services/vpn/faq.cfm#outside_computers
Thus if you are in another country (thus, you are off campus), and you are trying to reach a non-Cornell resource in another country, Cornell's VPN service will not help you do this.
One person's recommendation
Used with great success by a Chemistry colleague during trip to China. His need was for a period of days, which was just under the duration of the free trial period. :-)