I picked up a few more performance tips from this article. Notably, to make links consistent by case. You’re liking already doing this as a single developer or perhaps a small team, but if there are many developers, I can imagine inconsistencies. Also you should always close your tags. If you’re writing proper XHTML, I’m sure you already are.

From this presentation, I picked up a few more tidbits. Never use the with statement. When it’s used, the javascript processor will have to examine the object (up the prototype chain) and the scope (up the scope chain) leading to expensive look-ups.

Never use eval if possible. This includes sending javascript strings to setTimeout and setInterval. Evaluated code must be compiled and interpreted.

Also this post discusses the potential security concerns and memory leaks associated with innerHTML.

Lastly, I want to point out an old tool that I was recently asked about for an IE6 problem. Drip can be useful for detecting those IE6 problems.