Note, though, at WD, our return rate is about 1% and the majority of these saw some kind of physical damage (e.g. were dropped). This rate is going down due to the use of fluid dynamic bearings (can withstand a lot of abuse) and parking heads onto ramps and sensors that detect free fall and park the heads. Note, too, that no small portion of our returns are No Problem Found.

Might I suggest something like the WD Passport as a backup device for your laptop?
http://www.wdc.com/en/products/index.asp?Cat=9