Be Right Back, Uninstalling

I'm just wondering if anyone knows of any secure freeware that could help me download videos from youtube, I need this for a school assignment and it would be nice if I could just directly embed the videos in the presentation.

Google flv converters. Convert and download as mpg or whatever you want.  ;D

I use http://www.downloadhelper.net/

I've always used http://vixy.net