What do you do when you suspect that a user is going to bad sites on a company laptop, but they've cleared their history in Internet Explorer and deny any wrongdoing? You use group policy to prevent them from clearing their history! The setting is in
User Configuration -> Administrative Templates -> Windows Components -> Internet Explorer -> "Disable Changing History Settings" or "Disable Configuring History". Of course, there are other considerations as well (anonymous web proxies or alternate browsers), but this is a neat setting to enable.