I combined a YouTube video search script with this forum today. By clicking on the
icon above the text box a popup window will show with the embedded YouTube search script. The script has the ability to search the YouTube API in all sorts of ways. I have altered the display to suit this forum and to output the video address. The videos can be played within the popup window and once a suitable video is found the address can be easily copied (along with the necessary BBCode) by clicking on the 'Copy' button. The copied code can then be inserted into the text area and the YouTube video will display within the forum post.
Tested on a Mac & iPad and Kindle Fire