FileSystemSnarl is a tool which monitors changes in your filesystem and shows notifications using the notification system Snarl.
There is no installation necessary. Just extract the archive and double click the FileSystemSnarl.exe.
First you can choose in the Snarl settings group if you want the notifications popup on the same local machine or if you want to send them to a remote computer with Snarl running.
If you choose to send them to a remote computer be sure to have the network feature of Snarl enabled.