As it stands it is only legal in the US - anywhere else in the world it needs a transmitting licence.

ivan4, how did you find that out? Their website says "pending FCC approval". I decided not to buy, based on that lack of approval (also on the poor quality of their website, generally).

From the Register GoTenna: How does this 'magic' work?

It seems that this really isn't really that useful unless everybody else also has one... especially in emergency situations. It would need to be adopted widely to be worth that price.

The range is abysmal and it only works if the other party has one as well. In an emergency you're better off having a pair of two way radios.

I wonder why cell phones cant be made to connect to each other creating their own network

This looks like a scam, nothing else. The alleged frequency is 155-154Mhz (or the 2 meter band) the range of a 2 watt transmitter in this frequency is (for rule of thumb) only line of sight plus 10%. Normal use range is around 1/2 to 3 miles outdoors. From one mountain top to another in perfect weather you might get 8-10 miles. I know because I am a licensed radio amateur and regularly use 144Mhz at 5 watts. The chances that this would get licensed for use anywhere in the world is virtually nil. As another poster said, buy a couple of two way radios. As another asked why can mobiles not talk to each other? Because the phone companies would not earn any money from that! Simple.

@esar
I think most today's cell phones can connetct to each other by bluetooth. Range is a problem, as it doesn't go very far (like 60 m or so). But yes, it would be much more sound if manufacturers would start thinking along these lines.

GoTenna: How does this 'magic' work? http://www.theregister.co.uk/2014/07/21/gotenna_talks_radio_bollocks_most_tech_websites_parrot_it/ It is also worth reading some of the comments - the technical ones are very good, the others are typical Register banter.
As Dax Wagner and nicho say, it is cheaper and better to use normal two way radios, they give better range and use normal voice.
This device is a supposed 'solution' looking for a problem and requires a very large number to be in use to be of any use. To get the large number out on the streets they would need to sell for less than $10 each.

@ easr: If cell phones could connect to each other or even form their own dynamic network, the cell phone network providers who sponsor most of the cell phones people have via their rates, would not earn a cent, right? I think that answers the qestion. It would be technically possible to have them connect. It would drain a bit more battery, since there would be a constant data overhead sent and received in order to maintain the network, but it would still be possible.