Hi Henry,
I don't know how fast these nests get built, but I noticed these two wasps nests for the first time, today. The one on the power pole, attached to the transformer(first 2 pictures) was about 20 feet up. It was on the corner of Pilon Rd and Bessette Rd in North Fairfax.
The second one was on Wagner Rd and was only about 4 feet off the ground attached to a tree branch.
JoAnne
(http://www.vtgrandpa.com/photos/albums/icestorm_080309/00120_G.sized.jpg)
(http://www.vtgrandpa.com/photos/albums/icestorm_080309/00211_G.sized.jpg)
(http://www.vtgrandpa.com/photos/albums/icestorm_080309/00512_G.sized.jpg)
(http://www.hunt101.com/data/500/medium/15768Copy_of_HPIM0104.JPG)
I caught this one in a live trap