Postsucker is a simple tool for showing what is POSTed to a URL. It's useful for monitoring POST notifications from web services, such as PayPal's Instant Payment Notifications.
It's supposed to be simple, lightweight and portable. It should run in any environment where PHP is allowed to write to disk. If you find a problem with it, please report it or contribute a solution.
It's very young and isn't suitable for a production environment.