Vonage has a program for global nomads who want to make cheap calls. It's a lot like the services that have been around for years from various calling card services, the only difference from what I can tell is the tie into your Vonage number, which is really the same as an account...YAWN.
I continue to be amazed about Vonage's lack of innovation. They can claim all they want to that they can do anything, but with so many 2.0 companies out there like clients Grand Central, iotum, PhoneGnome and others like Roam4Free, Jangl, Skype, GizmoProject, Yahoo, etc. really innovating, not simply bringing the PSTN or PSTN era service to IP, but really looking at how 2.0 applies to voice I'm amazed the Vonage Board of Directors isn't calling for someone's head.
Vonage's may sell on price, but companies that some call Vonage like including Earthlink, SunRocket and Lingo, as well as some of the cable MSO's are making 2.0 like moves, while Vonage remains in what I call the land of 1.5 and all that differentiates them from 1.0 PSTN carrier is the RJ 45 and a different billing address.