I recently ran across a tool called Zamzar. What Zamzar does is convert any file you want into another file of your choice.
The best benefit is that the software is used completely online, no downloads necessary. Zamzar simply uploads the software and then emails the converted file. It is very helpful if you have a .docx file and need it converted to a normal doc file.

Recently Zamzar has introduced the ability to convert URLs to files. This includes converting Youtube videos to the video file of your choice. Now I can download a massive you tube video collection and convert all my documents to pdf for free.