Hide-A-Folder X for Mac

From Cryptonic Technologies:

Hide-A-Folder is a low level security application. It is used best in an environment where the security of the data is not of the utmost importance. The idea is to be able to keep your information away from prying eyes, snooping employees, or kids who may accidentally damage or alter your files. It works by making folder(s) invisible, which can be made visible easily by anyone with skill or want. It features password protection and the ability to hide/show multiple folders at once.