I use the trick Gil mentioned with power lines, too, when available. It is death on them. I tie the plastic ones onto a reel and rod and just throw them over the bottom wire on a power line. The bottom wire is always neutral (not hot). This is true on single phase and three phase lines.
I set them up this afternoon, but the wind was so bad I couldn't stay out in it. I killed two, then "called the dogs and peed on the fire". It must have been hitting 35-40 mph in gusts. First time I ever saw it blow so hard it would stop the Mojo from spinning. Nonetheless, I could tell it tolled some in. There'll be better days than this to shoot (tho' not many, season goes out Jan. 5).
SRH