You can get a pretty sweet arm bar from the kimura set up that I like using, if they defend the kimura you bring your top leg out and over the head and invert through putting that shin under the armpit then putting the leg that was on the bottom over the neck and straightening for the sweep to arm bar... I'm searching YouTube for a video of this as you'll probably go cross eyed with my awful explanation.
Found something similar, I like to get the sweep to spider web for the finish.
http://youtu.be/u0CFjIqhd50