My father-in-law had this hard drive that had quit. So we did the old trick of freezing it first, then hooking it back up and trying from that point.
It did work for a few minutes; unfortunately his computer is slow, so about two minutes of that was just getting it booted. After that there was one minute of seeing that it was in fact listed in "My Computer". We accessed it and copied a couple of files, about 100MB of data, then the drive quit.
So I figured that if freezing it does something to revive it a bit, then it quits again, maybe it is because running it makes it heat up. Solution: Keep it frozen.
We stuck in a plastic bag in the freezer to store for a few months before we finally got around to more data recovery. We got an extra (long) SATA data cable for it, and spliced some wires to extend the power cord, then left the hard drive in the freezer while we hooked it up to the computer.
Sure enough, it ran for quite a while time this time. We recovered about 1.5GB of data including the mastering tracks for my wife's first album.
After that the drive was completely dead instead of mostly dead, but we did at least get something back.
The only thing better than doing this is backing up your drives before they go bad.