What's the best way to reload data into multiple usercontrols on postback?

[Gummy]

Hello,

I have a multiple user controls (15) that are dynamically added to a
PlaceHolder everytime the page is loaded. In a listbox on the left (in the
user controls), I can select an item, click a button and it moves the item
to the listbox on the right.

All works well, but since it does a postback for each click all the other
controls need to be reloaded (Control.Add...) to the page even though their
data didn't change. I have set those controls with a ViewState so I don't
need to reload their data from the database, but it still seems very slow.

So far I've seen information about adding the controls in the OnInit method,
but they still have to reload all that data/

Can anyone suggest some articles or other information about the best way for
me to have multiple listboxes full of data that can still reload quickly
when I do a postback?

Thank you.

-Gummy