Here is an example of socialising a YouTube video with Facebook’s social plugins. In this example, I’ve integrated a simple video with the Facebook Like and Comment plugins. For styling, I’ve used the Twitter Bootstrap CSS Framework.
https://gist.github.com/4730032
The major components on this page (youtube video, facebook plugins) are easy to integrate from elsewhere – for example, you can copy the embed code from YouTube by right-clicking on a video and selection “Copy Embed Code”. Facebook lets you use a code builder to customize the Like and Comment plugins, which you can then copy-and-paste too.
Only the styling and structural components on this page required hand-coding. Try changing the YouTube video, or the location of the Like / Comments to see just how easy it is to modify the code.