i've heard about this but just recently read it. the site has the pdf link
http://storagemojo.com/?p=378
some points i thought was interesting:
- hd temps have a sweet spot for the lowest failure rates. about 35-45c. higher than this range failure rates increases but lower temps are even worse.
- older drives are more affected by heat than newer drives.
- hd brands do play a role in failure rates but google would not publish the data. [maxtor?]
- almost 50% of drives may fail without SMART warning.
- newer drives sold today show less failure rates than older drives and is perhaps due to new drive technology
- drives have high infant mortality. drives should be used excessively and if it fails early replace using the warranty. if it doesn't then it's likely going to last a long time.