Video Editor that allows users to assign a Creative Commons license (CC-BY) to their videos. To mark videos with a CC license, simply click the radio button labeled "Creative Commons Attribution license (reuse allowed)" at the time of uploading, or go to My Videos, select edit for the video for which you wish to assign the CC license, scroll down to Broadcasting and Sharing Options, and select the CC option.
Those wishing to find content they may use under a CC license can find it in the Video Editor by simply clicking the CC tab at the top of the page. You can conduct a keyword search, with only CC-licensed videos appearing among the search results. To add a video to your storyboard, click on the 'plus' symbol (+) and remix away!
For more information, including important details about the rights and responsibilities involved, see YouTube's page on Creative Commons. You can view the terms of the CC-BY license at the Creative Commons Web site.