My Marlin 1894 sports one of the Williams FP sights linked to by mehavey. I love it.
I've been meaning to change out the sights on my 1985 Guide Gun, and have been eying the Skinners. I worry about having to change out the front sight on it, though, so I haven't gotten around to it.
“There are three reasons to own a gun. To protect yourself and your family, to hunt dangerous and delicious animals, and to keep the King of England out of your face.” - Krusty the Clown