Nothing slows down a good presentation like waiting for a YouTube video to load.  There is a better way.

1. Download and install Real Player 11.
2. On the video's YouTube page, click to upgrade the video quality to the top quality.
3. Once the page has begun loading the higher video quality, click the Real Player download box.
4. Once your video has downloaded, open the download manager, mouse over the completed video and click Convert.  Select Windows Media (.wmv) at full quality as your preferred format.
5. In Powerpoint, click the "Movie" button and select your video.  If you would like to play in full screen, you can resize the video by clicking and dragging the corners.