The real question is if the HD platter/head is toast or if the file system is just corrupt. If there is physical damage, then short of expensive service, there is absolutely no hope for recovery.
If the file system/OS is simply corrupt and not bootable, you can boot the computer into target mode (hold T key during startup until you see the firewire symbol). Then you can plug your computer into another computer and copy off the files you want to save. This can be followed by various methods to try to repair the corrupt drive and/or clean wipe.