This Widget will display the YouTube videos that you want and the only data needed are the video URLs. There is no need to get YouTube API.
Berri YouTube Gallery gives you possibility to show a YouTube video gallery with customized appearance on your sidebar and all you need is to write the video URLs in the widget control panel. There is no need to register or to get YouTube API. Easy to customize and you can insert an image in the video thumbnail.
Comments, questions and bug reports are welcome: http://www.berriart.com/berri-youtube-gallery/