Once again chiming in with more than you might want to hear. ;). You can add very basic IE 5.0 support a couple ways. The very simplest would be just adding some sort of hook, basically, that checks if IE5 and then checks for the existence of a specific function that the user can choose to implement and then calls it. Least clutter to the code, yet still lets people account for IE5, if they have to, without having to modify your script. Personally, I’ll have to add in some code specifically for Flash and NS6, so it’s moot for me, but I know I would appreciate it otherwise, as many of us still have to meet client requirements of IE5+

In the last version I commented on swapping in and out a body class that hides all descendants with a certain class and then having one css rule such as
body.currentlyHidden .hideOnMenu{visiblity:hidden;}. This would only require a couple of lines of code (the test for IE5, and then assigning the body class with a RegExp to not touch any other classes on it), but it does have at least one shortcoming — it can cause stupid IE to refetch background images, if they depend on selectors with body.class, as it has to refigure that .css and doesn’t cache .css background-image).

Since then I have considered what may be a cleaner possibility. It should be possible to somehow add and remove just a .hideOnMenu{visiblity:hidden;} rule to the stylesheets. Add the rule on mouseover and remove it on mouseout. Haven’t thought about it too much, yet or even loooked at testing it, but this might be the simplest way, and actually wouldn’t take much code, either.

Expect another post, as soon as I have something to show. And a very big thank you for including me in such respectable company.