does windows recognize the drive when it is connected? its worth trying to see if you can transfer the files off in this way. i'd see how much the drive is responding to you, hopefully you can still transfer files off before it dies. there are recovery software suites available but i don't think they will work in case of mechanical failure.
if you damaged the r/w heads inside or threw things out of alignment you might not be able to read the data. i'm sure there is an option out there to get the heads fixed and to transfer data off but unless you're talking about some very important data the price isn't worth it.
two suggestions for the future:
-back up all of your data in multiple sources
-invest in an external hard drive equipped with a rubber shell. i think lacie made one that they proved could survive quite a fall and still work. hard drives can be quite fragile if bumped in the wrong way.