I am completely comfortable with the idea that there are countless people out there far, far smarter (s-m-r-t-r) than I. What's so great about that idea is that I can program much faster and more cleanly using libraries and works that others have built and even built upon. I prefer to do things myself, but sometimes you just can' turn out the stuff quickly enough. Even more so, sometimes you just can see the forest for the trees and you need a little boost in creativity.
There are several very cool libraries for Javascript out there. This page in my notebook is just a quick list of the ones with which I've taken the time to tinker.
To do... Prototype Javascript Library
To do... Scriptaculous Javascript Library
To do... jQuery Javascript Library
To do... MooTools Javascript Library