Q:

Improving Cmd-` app window switching - MRU order and/or preview

Using the Cmd-` shortcut to switch between windows in an application is inefficient for me when there are more than two windows since they are cycled through in a fixed order and there is little visual feedback to show which window has been switched to.  Is there a way to change the behavior so that it works more like Cmd-Tab?  Specifically, I would like to be able to switch between windows in most recently used order and/or display an icon or preview to show the window being switched to. 
I'm using OS X 10.7.5. 

A:

You can use an app called witch. 
http://manytricks.com/witch/
It allows cmd+` switching using MRU order and a popup overlay similar to the default cmd+tab overlay.  You can also, optionally, show window previews and many other customizations.