what is the safest and "virus free" way to import you tube video in final cut express? Is there a way to save "you tube video" as a local file and reuse it in final cut express?
Since you're using Final Cut, I'm assuming that you're on a Mac.
You can save YouTube videos using YouTube Downloader+ (here's the PC Version). YouTube Downloader saves the videos as FLV (which cannot be imported into Final Cut) so you will need to convert them to QuickTime format using a program such as Perian.
If Perian doesn't work out, you can find more options for converting FLV here.