You guys are really pushing your luck with WD drives - I have seen a lot of them fail and not be able to recover anything on them once they do fail. They also have some short factory warrentees - Seagate also had some failures but have 3 and 5 year warrentees now and the bigger drives are very cheep - I get 300gigs for about $110 so you really can't beat that. Have seen a lot of Toshiba laptop drives fail after a couple of years of daily use and a few OLD 100meg Maxstor drives that just don't die but who needs 100megs of drive space nowadays. Samsung has some nice quiet cool running drives but I can't seem to get them from my Vendor anymore.
Try putting it in the refridrator overnight then see it will boot if it will but you don't have time to pull data off while running OS setup OS on another drive and put failed drive on secondary again put in cooler and try again. most hard drives fail when they get the hottest and cooling them down will allow you to get your data off till it warms up again or you can simply rig it up and leave the drive hooked up in the refrigerator till you get your data off. Also if arm is stuck you can try tapping or dropping it ever so softly. I had so many drives fail a few months ago. One of my users and while I was working on hers my own failed in my workstation both of them I was able to cool them off and get the data off but was unable to do a ghost on either one but that was ok. My grandfathers failed a few weeks later but he had a drive that put the firmware on the disk and it became corrupt and the computer could not even recognize it as a drive anymore. I have had really good luck with western digital but its heat that kills them. These dells they fail in are not built for air circulation and the drives get horribly hot.
USB 2.0 inclosure for about $40 (prices vary) that will take any size drive - you should consider if you need fan cooling in the external enclosure or not because some run hot with heavy continuous use.