Hi, I've put two very short tutorials online with some c&p from the docs and source code of Ext JS 3.0. The goal is to make Ext users aware of a couple of new features that are not given enough importance or not yet fully documented.
id vs. itemId
What is the difference between id and itemId and why you should use the latter when possible.
Using ref config option in Ext 3.0
Using ref config to place a named reference of a Component into any ancestor Container. I think this one is a huge thing.