It's an interesting idea, but I can't really think of a situation when this would provide an advantage over using a radio walkie talkie. Maybe because the signal can't be intercepted as easily? But then there's the awkwardness of having to aim the device. Articles about it frequently suggested it could be used as a wireless intercom.
Eugene Guard - Nov 14, 1960
Palm Beach Post - June 4, 1961
Popular electronics - Feb 1961 (via RF Cafe)