Ok so shady might have been the wrong word choice.
Here is how I see it.
With Vonage, you get stand alone hardware, it connects to your broadband, and goes to a phone.
As long as your broadband connect is active you are going to have phone service.
With Magicjack, you get a usb device, if the computer is off, so is your phone. Also being a USB device I'd be willing to bet that if the phone rings while your flying your going to lose CPU cycles.
With skype its all software, again if the computer is down your not going to get calls.
However you would probably get a notification that someone called when you get back online.
Which has its own advantages.
