Good use: Find two, leave one two-way radio at an ambush location of your choice, get in your sniper/observation point. When they approach that area you can talk to them as if you're within talking distance...use your imagination at that point
You "Hey, who's there? I'm friendly!"
Them "Where are you?"
You "I'm in front of the fire station"
Them "wtf? where is this guy? Is that a walky talky on the ground?"
*BOOM sniper shot from the ridge*