A few months back I came across this great program called 'Hard Disk Sentinel' for my Extreme Media Server (HD Sentinel's Site).
For the extreme number of hard drives that we have to manage, a program that monitors the health of your drives is essential. This program not only makes it is extremely simple, but also supports the port multipliers and SiliconImage Controllers we use.
Here's a couple screen shots from my EMS:
The first one is a summary screen that can hover in the corner showing the current status of each drive.
This one is if you enable toolbar reporting - notice all the drives are listed with their current temps - the boxes will turn to yellow and red as issues warrant.
And here is a screen shot of the main program window: