[cd34]

if you had GPRS Edge service on your cell phone, and a bluetooth adaptor, and portable power like the solar panel from scottevest, you could even take your vonage number with you anywhere you had GSM service.

Or you can set your network unavailability number to your cell phone.

I find that once in a while the box just blinks -- and you have to power cycle it. But, I've never really had any problems with it.