Let me know if you have a Scorpio Black that clicks a lot. Scorpio Blacks don't get along too well with OS X's APM.. and they park their heads like every 5-10 seconds when they are idle. After like 3 days I had my new Scorpio Black up to like .. 4,000 load and unload cycles, and the drive is rated for 300,000.... at that rate it would have lasted me only 6 months or less.
I have heard some have the problem and some don't. In any case, if yours does, get HDAPM.. just search the threads on here for HDAPM. Scorpio Black Clicking or Clicking Hard Drive will also yield results. I searched this forum after I discovered the problem on mine.
Ended up taking it back and getting a Seagate Momentus 500GB 5400rpm. Just so it is quiet. If you have any questions pm me on here, or get a hold of me on my site, in my sig.