QuirksBlog: style vs. className

An interesting article addressing how to use Javascript to adjust a web page element's style: QuirksBlog: Benchmark tests: style vs. className
I hadn't thought of changing the class to adjust the style, but it makes sense. One of the things that threw me for a loop about Todd's Javascript problem of last week was that the script adjusted style by appending a class: at first it was class="on" and then it was class="on over".
I generally look at the Quirksmode website whenever I am trying to do something in Javascript, but I obviously need to start keeping up with the blog there. I found the Quirksblog entry from following the Surfing Safari weblog, in which the principal developer of Safari recognized the performance problem noted by Quirksblog as a bug in Safari.