Better modern backgrounds for web page elements

This post is inspired by banners from Deus Ex.

Backgrounds are remarkable and I can see it as a huge potential for the web today.

General question is what are the means of achieving something like that for webpage elements?

1. jQuery background animation? Can move backgrounds horizontally or vertically. What about diagonal?


2. Gif on the background? But how one creates such seamless "video patterns"?


3. Background youtube video loop? But then again - how do you create such video?

Practical solutions and general thoughts on the issue are appreciated :)

P.S. I am not a professional designer.