Zamzar is a free online file conversion web application that can not only convert videos off the Internet to AVI, MPEG, 3GP, MP4, MOV, etc, but also converts between audio, image, and document formats. Paste the URL into Step 1 and then convert the file to your favorite format.(It emails the video)

ClipNabber allows you to download videos from YouTube, Metacafe, etc by simply copying and pasting the URL. You’ll then get a link whereby you can download the file to your computer, iPod, iPhone, or any other media player. You’ll need to have an FLV player for the YouTube videos. Quick and very easy to use!(It doesn't convert videos and you also need Java installed on your computer to download.)