So, as I've recently learned, reaction wheels rotate a craft with Newton's Third Law, remain spinning while the craft should rotate, then stop, resulting in no rotational speed, but after having rotated the craft, yes?
So what's to stop you from tying a brick to your space craft, and throwing it, as to send you forward and the brick back relatively, until the brick pulls on the rope, and nulls to change. Would this work? If not, why not? Could this be used for maneuvering position wise rather than velocity wise? Could you create a massive object with an incredibly long/strong rope to say, go to the moon(but have no change in velocity other than gravity and other expected things).
I figure that in order to pull the brick back, and not end up in the same position you started at, you'd have to anchor to something to increase your mass, say the moon.