If you can connect the drive as a second drive, say as /dev/sdb or something similar, can you access it a all with, for example, cfdisk /dev/sdb? If you can, don't try to do anything with cfdisk but rather try the fsck utility. You should read the fsck manual page before executing the utility and make sure you understand what it's going to do before you attempt using it. It may -- may -- be able to fix a corrupted file system, just keep in mind that you do not use it on a mounted drive partition.
There is a gadget you can buy (for not much money) that's called a Universal Storage Adapter. You connect it to a USB port then connect a 2.5", 3.5", 5.25" IDE or SATA drive and you can access the drive and recover files from it (if, that is, the drive is not totally destroyed). The one I have is call a NexStar, made by Vantec and has worked fine for me recovering stuff from otherwise unmountable disk drives. A quick Google search for "Vantec NexStar Universal Storage Adapter" will turn up a bunch of sources for one of these (I bought my from Frys).
And, if you are successful getting your data back... CD-ROMs and DVDs are good back up media to keep in mind, eh?
Hope this helps some.