Google rolled out "YouTube content rating" system to all U.S.-partner uploaded content, that'll potentially be of great value to you as you earn money from your videos on YouTube.
"Now, when you upload a video that doesn't have a specified content rating (i.e. MPAA or TV rating), we ask partner to rate content in these five categories: 'Language, Nudity, Sexual Situations, Violence and Drug Use'. Our content rating system allows you to assign ratings to your YouTube videos either during upload process or afterwards. The ratings are reversible, meaning that you can change or remove them at any time if you feel they no longer accurately describe your content," explains Google.
"Our first 10 partners to add content ratings to 100% of their content by July 31, 2010, gets a special prize! We're asking you to complete two steps: 1. Add accurate content ratings to new videos, and 2. Go back to all your old videos to add appropriate content ratings there, too."