LeechBlock has helped me to be so much more productive. From blocking YouTube to other sometimes time-wasting sites, I've found myself actually doing more instead of just planning to do more.
The interface is easy-to-use, and the GUI is simple but effective. If you're hesitating to try it out, really, please don't. It will help SO much.
Thank you, LeechBlock!

(As always, this is a completely honest review from a regular human being ;)