Yes, there is a lot of content on YouTube completely inappropriate or unrelated to a classroom setting. However, there are a lot of videos on this site that could be a great opening hook to a lesson, an enhancement to an experiment or a fun way to help students learn Pi. However, most school districts block this site on their internal internet. Not to fear! With sites such as SaveVid and KeepVid, you can download the videos as a QuickTime or Windows Media Player file at home, then bring it to school on a flash drive or your laptop to show in your classroom! All you need to do is paste the URL into the url box on these websites and they offer you a myriad of downloading options. Check it out :)!