I ran across a very useful collection of compressed versions of popular JavaScript libraries today, including Scriptaculous, and Prototype. The Prototype library compresses down from 70k to 30k, which is pretty impressive. I’m becoming more persuaded daily that MooTools is a better option, though, as it offers you the ability to pick and choose which pieces of the library you wish to download, and offers compression on your custom built package resulting in vastly smaller file sizes than the Scriptaculous/Prototype combo.
If you want to compress your own JavaScript or CSS, there are a host of utilities out there for just this task. See comments on this blog post for a laundry list of options.
