Turn dock animations off, maybe even turn anti aliasing off (though text will look a lot crappier), def turn genie effect off (if you haven't already).
Nothing, however, will make you see similar speeds to what you did in OS9, and that is true no matter what machine you switched over on.
Just learn how to take advantage of the multitasking and at least that aspect of speed and productivity will be noticable. Just don't expect OSX to be nearly as Snappy?