Software and Computer System Company (SCSC) has released Scannerz Lite (http://macte.ch/Gy0hy) for Mac OS X. It works with Mac OS X 10.5 or higher and costs US$7.95.
Scannerz Lite is a simpler version of the Scannerz app. It employs the same advanced hard drive analysis algorithms used by the fully featured Scannerz, but has a simpler user interface. The tool is intended to be used by people that want an inexpensive product that can thoroughly test their drive and system, quickly and easily, according to SCSC.