Recently while trying to broaden my horizons I started to learn php, after writing the basic hello world app and a basic script to query a mysql database I stumbled across phpmyadmin. I had trouble getting it configured correctly for the raq server that my site is on. I wrote a quick script with phpinfo() to get the information I needed. What does phpinfo() tell you...from the phpmanual.......
"Outputs a large amount of information about the current state of PHP. This includes information about PHP compilation options and extensions, the PHP version, server information and environment (if compiled as a module), the PHP environment, OS version information, paths, master and local values of configuration options, HTTP headers, and the PHP License"

I did a search on google for phpinfo and was amazed to find hundreds of websites that freely divulge this information. Go try it yourself. At the very least and scripts that contain phpinfo should be in a protected directory. Don't know how to protect a directory take a look at this tut
I am no security guru and all the information that phpinfo dumps may be able to obtained through the use of various tools or methods but having all that information in one place sure gives the kiddies a head start.
In summary if you use phpinfo for configuration or debugging make sure you put it into a protected directory.