I've seen dual-display setups where you can drag a window that's maximized in one screen to the other, but I can't do that on mine...is there some option hidden somewhere to enable this?

I don't think Windows alone will do it. I always make mine windowed to drag them. There is outer software out there for multi monitors that adds features. Check Ultramon for example.

I drag bewteen monitors, but the windows are not maximized. I'm curious to know how it's done w/ maximized windows.