I know the effectiveness, like GobblerD, of hunting w/ decoy heads.
I've got about 250 silhouette heads in various poses, feeders, uprights, resters, and high head sentinels mounted on 1/8" welding wire in both snow and canada geese. Like my full silhouettes the heads are made out of corrugated plastic sheeting and when we hunt fields w/ high stubble or corn stalks, we mix the heads in w/ the shells, silhouettes, full bodies and wind socks to expand our spread w/ little extra effort and weight. While hunting geese in Canada we have hunted only with the heads in uncut barley fields w/ great success.
I love hunting w/ silhouette decoys and have made turkey silhouettes to create a flock effect, primarily as feeders and resters. The real beauty of silhouettes is that when they're placed at various angle to each other, as you move and your perspective changes the flock seems to move. I've never had birds spook when they get into the "flock" they just seem to act somewhat indifferent to their surroundings. The silhouettes are light and you can carry a bunch in a nylon camo bag w/ straps. We haven't done it yet, but have discussed putting out a bunch of silhouettes w/ a friends full strut DSD next year on some places we hunt that have big flocks of turkeys. I usually run-n-gun, but this might be a plan for day 3 or 4 when you're worn out and need to sit and rest.
Craig