On Christian Stocker's blog today, there's his experience with testing his code coverage visually with the help of the SimpleTest framework.
But one thing I saw over at PHPUnit2 and badly wanted to have, was the Code-Coverage Analysis. The pure coverage data comes from Xdebug PHPUnit2 "just" displays it nicely based on that. A quick look into the code revealed that it was easy to just use the CodeCoverage classes and so I integrated it in our testing framework.
For our CMS, we use SimpleTest as testing framework. We used it in other projects, and as you should never change a running team, we sticked to that for Flux CMS as well.
He gives his example of how the code coverage looks, and gives the eight lines of code that it took to implement it - nice and simple...