All frameworks aside, what are some of the common helper functions/prototype methods you use on a daily basis?

Please note I am not arguing against frameworks. I've simply found that the majority of what I do on a daily basis can, most often, be done with a few dozen Array, String and Element.prototype methods. With the addition of a few helper functions like $ (getElementsById) and $$$ (getElementsByClass), I am able to satisfy some of the core benefits, however basic, of a much heavier framework.

If you were to collect a small library of basic methods and functions to replace the core functionality of some of the popular frameworks, what would they be?