It's not just a great security tool but a general improvement to your browsing. It can stop YouTube videos that auto-play, block those pesky flash ads, and any other scripts that interfere with your browsing.
This script alone makes Firefox worth using if you're not already. But to those that don't like using Firefox, there is an alternative for Google Chrome. The word alternative is used very loosely for Chrome's FlashBlock extension. Just as the name suggests, it blocks Flash from running until you choose to allow it. Just click on the Flash object and it will run as if nothing happened. The downside is that it isn't as advanced as NoScript but it is a start. If you have any other alternatives or suggestions, leave a comment and I'll check it out.
Difficulty Level: Easy