Messing with creating custom layouts and why not use CSS3, I have stumbled accross a demo of an accordion style menu (http://www.paulrhayes.com/experiments/accordion/) and Bucs in the forum has been waiting for Sencha to create it but it peaked my interest also. So here it is!
GitHub - https://github.com/mitchellsimoens/E...ccordionLayout
Demo - http://www.simoens.org/Sencha-Projects/demos/
Let me know what you think!