How to sync my iphone with an external hard drive through itunes?

I have no space left on my computer and I need to update my iPhone (4.2) I thought if I could sync it on itunes and back it up on my harddrive. It's 32GB and I've filled it up with movies and TV shows that I don't want to loose, they just wont copy onto my computer. How do I do it?How to sync my iphone with an external hard drive through itunes?Hi, you can trasnfer the entire iTunes library to an external drive. I did it two weeks ago using a software called Tuneswift. http://en.kioskea.net/faq/10073-transfer鈥?/a>