phploc is a tool for quickly measuring the size of a PHP project.
I just made a small contribution to it by adding counters for constants and class constants. My account over at github is located at http://github.com/christeredvartsen. Sebastian pushed it to the master repository about an hour ago.
I have also patched our phpUnderControl installation at work to output this information and contacted Manuel Pichler about it. More about that later!