I'll have to scour this discussion on how I can improve the workflow for developers at my company.
I have to look into Xdebug to use on our development servers. This article has some information and images showing off how this can be used. Hopefully, there's a Gnome version of KCachegrind (though it really wouldn't matter as I should be able to run it under Gnome anyways).
(Got this via the Baton Rouge Linux User Group mail list)