However, I'll try to explain these two screencast.
This video shows a saved version of Ext JS Home Page.
I didn't add to project Google Analytics unrich.js file but this should be included without problems too saving other 15Kb.
As You can see (I hope), the result is even smaller on page, just three tags, using IE5 compatibility one, instead of 8 inside page ... these are few bytes less than original and layout is even more clean than ever.
Prototype and Scriptaculous in less than a minute, from 230Kb to 38Kb
You just need to upload these sources and with a click You'll download full Scriptaculous enviroment, reducing size from 230Kb to 38Kb.
Using client compression too, every gzip or deflate incompatible browser will download about 90Kb instead of 230Kb, reducing bandwidth about 38% of original.
Sorry for missed audio and bad video quality, I'll try to do something better next time, ok? :-)