prototype / scriptaculous - 2 Questions, may a suggest for a recipe or a screencast

Hi folx,

as I was looking for solutions for some AJAX challenges, I thought,
that other people are interested as well in this approach.
May Ryan or Geoffrey are interested to make a little recipe /
screencast out of that.

So I try to find clue's for following challenges:

- AJAX progress - loading - image should be visible until the last
selection has been made.
Lets say, you have an observe_form / observe_field, and you have
multiple filters with some checkboxes and a progress bar. When you
make several selections, normally the ajax loader is invoked for each
event on the observer.
But this looks ugly, at least mine does.

So, here's the question... Does anybody know, if it should be done
with something like a queue for ajax calls or do you have another
approach?
Is there a best way to do that?

- showing / hiding many records in the list with a transition gets
veery slow
while trying to make a smooth animation to fade out, blindup filtered
records, I get a browser performance issue.

Try to bilndup more then a hundered items and the browser gets a
performance problem.
Is there another approach?
I tried it with and without DB Select, DB select was not the
bottleneck.

Thank you for helping in advance

kind regards

Rafael