Is this the link you want to the Saturday Night Live history class taught by Jerry Seinfeld?
Hope this helps.
Check out the Freemake Video Downloader:
It allows you to download video clips (or extract the audio only) from 50+ sites including Youtube, and save the video as an AVI, FLV or a number of other formats. You can save the file to a jumpdrive and, presuming you have a player, show it at school.
Another possibility is to use Zamzar (www.zamzar.com) which is a free online file converter. Very simple four step process, all you need to do is select the URL function in Step 1, paste the video's URL into it, then complete the remaining steps. Anywhere from immediately to a few minutes or more (depending on traffic and your connection speed) you will have your video in whatever format you selected in Step 2 delivered to your email. I use it all the time. I also have the SNL skit on an external hard drive and use it for teacher trainings that I do.