The awesome feature is called click to play. All it does is stop a plug-in like flash from loading until you click on it. It has made me realize how ubiquitous flash is on the internet as well as many useful features. Before using the experiment flash would run in the background and hog 20% of my CPU even at idle. With plug-ins blocked my pages load faster and my laptop doesn't burn a hole in my leg.
As I mentioned before, this is only available on the dev/beta channels of Chrome. It isn't just a simple setting either. You'll find it, along with other Google Labs, in the about:flags tab. After that you just enable it and head over into setting to set the plug-ins to click to play.