EXCLUSIVE: Vonage, the disruptive voice-over-broadband company has yet another trick up its sleeve, which is going to cause even more consternation in the phone company camp.

Last week, on a miserable typically East coast winter day I braved the elements and visited Vonage’s austere offices in New Jersey to have a confab with Jeffrey Citron, the entrepreneur cum raconteur. I complained to him that most of the readers of the weblog had been want a portable version of the Vonage service which can run off a PDA or a Laptop. His response: “Is this a softball question?” Not intentionally, I remarked. There are many who would even laugh at the suggestion that I asked a softball question.

Nevertheless, during the course of a conversation, he told me that the company had developed a Beta version of a “softphone” a piece of software that resides on a PDA (read Pocket PC) or a Laptop and can connect to the internet using a WI-Fi connection. This also comes with its own phone number and can be mapped with your local phone number (assuming that you use Vonage phone service.) A Mac OS-X client is in the works as well and will out fairly soon.

So when will this be available? Citron, refused to comment when but this morning I got hold of a PC-version of the beta software and have been making phone calls with it. Works, as expected just like a Vonage Phone.

I think this is a pretty significant development, for by signing up for this service which is going to cost about $15 a month, you don’t need to lug around an ATA and never miss phone calls to your broadband phone line. Now assume you can run it on a SmartPhone powered by Microsoft OS or a Palm OS! (Bill put some dollars in these guys for they are the sole reason why someone might actually give a damn about Microsoft-based SmartPhones.)

This is not such good news for cellular phone companies – why because many hotel now offer Wi-Fi access, and we can now receive phone calls when under Wi-Fi coverage. So no need to waste minutes on your cell plan, and you can cut monthly phone bills drastically. This is even worse news for long distance providers because it eliminates the need for a long distance calls, and of course the Baby Bells are at risk as well.

I cannot wait to take this phone number and go to India to visit my folks and have my office stay in touch with me using a local 415 number. Actually it might be great way for many reporters to file from the field. (Of course me being me, I assume that most of the places I visit will have broadband, for otherwise I don’t see any reason why to visit those places anyway! – Just kidding!)

What do you guys think? Love to get your response and thoughts on this.