Just found this on my Google Tutor
When you're searching on Google, we think you should have the choice to keep adult content out of your search results. That's why we developed SafeSearch, a feature that lets you filter sexually explicit web sites and images from your search results. While no filter is 100% accurate, SafeSearch helps you avoid content you may prefer not to see or would rather your children did not stumble across. We think it works pretty well, but we're always looking for ways to improve the feature.
Today we're launching a feature that lets you lock your SafeSearch setting to the Strict level of filtering. When you lock SafeSearch, two things will change. First, you'll need to enter your password to change the setting. Second, the Google search results page will be visibly different to indicate that SafeSearch is locked:
Even from across the room, the colored balls give parents and teachers a clear visual cue that SafeSearch is still locked. And if you don't see them, it's quick and easy to verify and re-lock SafeSearch.
To use SafeSearch lock, go to the "Search Settings" page on Google.