Very easy for u with E.M. Youtube video download tool.
Just download youtube video, then convert the youtube video to wmv or AVI format, then import it to your powerpoint.
(1)Install and Run E.M. Youtube video download tool.
(2)Play the video on the webpage.
when the video start to play , it will be sniffed and downloaded automatically.
http://www.google.com/search?hl=en&q=%22E.M.+Youtube+Video+Download+Tool%22&btnG=Google+Search
(1)Download youtube video fastly and easily;
(2)Burn Youtube video to CD/VCD/SVCD/DVD disc;
(3)It can search any flash video from many websites at the same time;
(4)Convert flv video to any audio include mp3, wma,wav,ac3,mmf,amr,ogg,aac..., to any video formats include 3gp,avi,wmv, mpg,mpg4,asf,swf,h264,mov,jpg, that can be supported by PSP,iPod,iPhone,Apple TV video,iTune,mp3,mp4,Zune,Cellphone,Digital camera,DV,CD/DVD/VCD/SVCD.
(5)List all cache flv video;
(6)It can also repiar and capture RTMP video streams.