But you get "Sorry Youtube not supported on your phone" message When you try to download the app on nokia n97. Youtube provides application for Nokia 5800. That app works well with Nokia N97 too.
When you open that application you see featured video, Top Rated, Most Viewed, Most Recent. You can search videos. The scrolling is fantastic. When you click on the thumbnails the videos starts.
The latest version of this app is 2.2.17. This have full screen playback feature. The video quality is also good.
Youtube application for Nokia N97 Download Link . Its a must have application for N97. Its officially from youtube.