This is a simple script I use all the time for debugging web applications. Send any variable to this script and it will output the key and value of the variable
Ok, I know that programming_http_environment_variable_listing.scandalz is a damn long name to remember, so you can also access this script via http://scandalz.net/env.scandalz.
There might be nothing here but send a form here or call it with a querystring like this and you'll see data