External Monitor and Spaces

I have a monitor hooked up to my Macbook and I am currently using it as a second screen rather than as a mirror. Now, I also carry my laptop around with me when going to class, and so I have Spaces enabled.

When I hook up my external monitor, Leopard creates another set of spaces. As in, if I'm on Space 1, I'll have my external screen like normal. But when I switch to Space 2, the external screen will switch to ITS second Space. When I bring up Spaces in Expose, I can clearly see a second screen next to each Space.

My problem is that I don't want it to work this way. I want the Macbook to have its Spaces, but not the external monitor; I want that one to stay on a single desktop. It can get annoying when I'm watching a video or doing something else on the second monitor and when I need to switch desktops on the Macbook, the external monitor does it too. The only options I can see right now are to either turn off Spaces when I hook up my external monitor (which I really don't want to do), or just manually drag apps when switching Spaces, which as you can tell, can be really annoying.

I've gone through all the Display and Spaces settings but found nothing, and have done some Google searching with no luck.

Come now, you're not going to force me to pick between one of the two options I can think of, are you? ;P