The aspect ratio of the movie is going to limit you. Your 22" monitors probably run at 1680x1050, which is a 16:10 format. A regular widescreen movie today in consumer format will run at 16:9. With 2 22" monitors, your effective resolution becomes 3360x1050 (even if the screens aren't bound as one, you still have that much pixel area). That gives you an effective aspect ratio of 3.6, much wider than a standard screen. So, in order to make the movie keep it's original aspect ratio (which is important unless you want to watch some really, really fat people act), the amount of screen space usable for the movie must have a ratio of 16:9, regardless of the fact that you increased the screen's physical ratio. This is going to be limited by the smallest factor of your screen, which is it's height, in this case, of 1050 pixels. So, in order to display the movie at it's correct ratio, you're allowed a screen space of ((16/9)*1050)~=1867 pixels. So, the maximum amount of space you can see your movie in is going to be 1867x1050 pixels, nowhere near your effective resolution of 3360x1050.
So, you can watch it across both...but not using the entirety of both screens. Why would you want to do this anyway? The LCD bezels will split the picture up, which would be pretty annoying.