Same thing I posted for someone else:
Well...there are a couple of options:
1) Take the drive to a data recovery center.
At that point you have to ask yourself if it's worth $500-$3000 to do so. Big businesses may do this (and even some small to mid-size businesses may, if they can justify it), as the price for losing, say, customer information can be even higher...
2) Try some home remedies.
Home remedies range from bizarre to OMGWTHAYS, but have been known to work circumstantially. However, if you do any of them, you're doing them at your own risk--nobody here is responsible for the end results, even if it makes it no longer feasible to do Option #1. Then again, Option #1 aside, some people see that they have nothing more to lose, so they'll do them anyway. If you are not comfortable doing any of these things, then ignore this entire section!
Many of them include, but are not limited to:
a) Putting the drive in the freezer under the assumption that it keeps the drive cool enough to prevent the platters from expanding into the read/write head.
Some have frozen their drives overnight, taken them out, hooked them back up, and were able to get some data off before permanent death. Others have connected their drives to an exposed external enclosure, and ran a USB or eSATA cable out of the freezer into their PCs (or power strip in the case of the power cord for an external enclosure.
I personally have done it both ways, and my results have been hit-and-miss--great when it works, though! However, I'd be cautious nonetheless simply from the condensation buildup. I can't confirm whether or not my positive results were simply correlation or that the theory about expanding platters and heat is actually true.
b) Dropping the hard drive in hopes to loosen the read head or stuck platter.
I personally wouldn't do this one simply because dropping any electronic device that's not meant to be dropped can often be a Very Bad Thing.
c) Taking the drive apart in a 100% (and I MEAN 100%) dust-free environment and putting the platters in another hard drive encasing.
I wouldn't do this one either--too much risk of making the data permanently unrecoverable, even by specialized data recovery centers. Also, who has a 100% dust-free environment in their home?