Uh, red cups.
There are some Universities (one that I know well I will not identify) where alcohol is a very serious problem on campus. As in several students to the ER with alcohol poisoning every weekend, many more so drunk they are passed out in public.
When said Universities mandated that on-campus parties that served alcohol do so in the red cups, the rate of hospitalizations decreased. Because you can't tell what's in the red cup. So you can be slurping away on one and your friends/co-students think you're having a beer, when you're having soda. It removes a lot of the peer-pressure thing.
So yea for red cups!