Presentacular allows you to add in all the script.aculo.us visual effects to your slideshow. I've already got a script that executes on showing a S5 presentation so it was a simple matter of adding in a class to say all my h1's. Now my headings smoothly fade in.
function addEffects() {
var elements = document.getElementsByTagName('h1');
for (var k = 0; k < elements.length; k++) {
var element = elements[k];
element.className = element.className + " appear";
}
}