Safari 3.1's Offline Features

The other day I wrote about the offline features introduced in Safari 3.1, and amachang has posted a detailed explanation of how to use them.

Safari 3.1 に実装された「Client-side database storage (SQL API)」とは何か？ - IT 戦記

I haven't read it in depth yet, but it's apparently a specification from HTML5, and it's reportedly already included in the Firefox 3 beta as well.

This looks like it could enable all kinds of possibilities...