From ZuCom Services:
This is a very simple application that when launched allows the user to set OS X (10.2 or better) to display "hidden files". This operation can be accomplished several different ways but most require some bit of command line interface, this took eliminates the need to use the command line and essentially wraps that functionality into a GUI.
(*NOTE, this has been tested on shipped versions of 10.2, 10.3, 10.4 and 10.5. Changing this setting requires the user to restart the Finder, which could potentially cause interruptions to other Applications or OS Operations. It is recommended that no other applications or operations be in process when using this tool