A very cool and under-utilised feature of PowerPoint is to be able to insert a YouTube video directly into your presentation. You will need to be connected to the Internet when viewing it though, unless you have the video on your hard drive.
Open the YouTube video, hit the “share” link, and then the “embed” link. Copy and paste the code in step 4 below.
Open PowerPoint, click the INSERT tab
Click the VIDEO tab
Click “video from website” (otherwise the “file on your hard drive” link)
Hit insert and you are done. Very simple.