Forgot to follow up sooner, but just mentioned the 200' or so of base, shoe and crown molding I put up, and that reminded me.
Somebody here mentioned hard drive magnets. Stuck a piece of masking tape on one, because it's pretty thin and I was dropping it. Then I just lightly ran it on the walls.ceiling with my thumb on it and the tape tucked between my thumb and forefinger. You can move it fast too. I used light pressure because it was brand new paint. Circular pattern of about a foot moving along. Beat the hell out of my 2 studfinders. And some studs weren't where I expected, especially near doors. Stops dead when it runs over a nail/screw. Then I stuck a little piece of masking tape there and moved on. Saved me a whole lot of time.
--Vic