What is a good way to archive iTunes movies? I have bought a decent number of movies off of iTunes through various sales. The issue is, they take up a lot of space on my 120GB hard drive. I want to free up space, but I also do not want to lose the movies I have put money into.

What is the best way to archive iTunes movies in such a way that I can access them quickly if I want to watch them? After watching my sister lose 3 years worth of pictures to a faulty external drive, I am not overly trusting of them. Are there any other options out there?
I know you have said you would rather not use an external hard drive, but my technique for storing films for iTunes is to store them on the external hard drive and link them to iTunes by dragging them whilst holding Ctrl and Shift (on a Windows machine) which rather than copying into the iTunes folder just short cuts to it effectively.