Following up on this post on the SitePoint blog about using XDebug on your application, Matt has posted some thoughts of his own on the subject, showing how to "really use" XDebug to speed up your application.
I was able to figure out how to use the profiling with a little help from the Xdebug docs and playing with WinCacheGrind. Since I never read a formalized method for properly using these tools I was hoping the SitePoint article would show me a better way. Unfortunately, I felt the article was thin on content and actually gave poor advice at one point.
To help remedy this, he provides a brief overview of exactly how he uses XDebug in an app to find his bottlenecks quickly and easily - including screenshots. He uses the Wincachegrind software to evaluate the results and to immediately spot the culprit. Following the screeshots and all, he explains what it all means in terms of how it's affecting the application and some simple things you can do to help speed things up.
Oh, and remember the issue he had with the SitePoint article? One little word they repeated three times - "cache".