I created this extension called Vertical TabPanel since Ext 3.1.1. As ExtJS currently just supports Horizontal TabPanel.
Basically this extension works the same way as the regular horizontal TabPanel except I added some CSS tweaks to push the Tab strip to the left.
I think this is quite useful in many projects.
Extension v0.2 updated to work with ExtJS 3.3.
Tested working on IE6+, FF2+, Chrome 4+, Safari 4+, and Opera 10.x
Check out the live example here
Download the whole example ( put files in folder : ext-3.3.0\examples\tabs )
Download the extension code only