being my browser of choice, click on "window" on the tab bar, drop down to "activity" and then scroll down the next window to find the flv file which should be loading, it will say something like "560kb of 11.5mb" or something like that, double click on that file and it should start downloading. Close your original window to speed up the download and then watch with vl player or some such. Hope this helps!

assume you have the youtube video page loaded and the clip playing - just though I'd better make that clear!

http://www.getvideomp3.com allows you to download YouTube videos and save them as mp4's, which QuickTime or VLC will play.

http://www.dvdvideosoft.com/ does similar job as the above, with some other bits thrown in

If you do, install 'Easy Youtube Video Downloader' as a Firefox add-on/extension. It adds clickable video download links to YouTube pages, and it lets you save the footage in a choice of formats. I use Firefox on my Mac, and it works a treat for me.

now offers it, have grabbed a few thuins that way-works fine

http://uk.real.com/realplayer

Tried a few of these... went down Soapdodger's suggested route and it seems to work well.
Cheers - I knew the Massive would be the people to ask!

www.idesktop.tv - free to use (though you have to sign up) and allows you to save in the format of your choice. I think it also sources videos from sources other than YT.