... on what kind of corruption you actually have. If you've head crashed, there is little hope of recovery but if it's just a logical problem, it may be recoverable. You say the system doesn't recognise the disk has even been partitioned. Does that mean you can still "see" the disk, albeit unformatted, or can you not see it at all? If the former is the case, you may have a corrupt Partition Table or FAT and the data is still there. If you can't see the disk at all, that isn't good and you are into the specialist recovery firms - this is not cheap.
If you can still access the disk, download TESTDISK (Google for it) and point it at the disk but on the first pass do NOT let it change the disk. If it can find any partitions on the disk, it should be able to show you what it can find if you let it go ahead, if so, run it again and let it repair the partition table. If it gets the data back, do not do anything else until you have a full backup of the disk! Another option is Partition Table Doctor but there are many others. The secret is not to let them change the disk until you find one that can find the pictures you are looking for.
If you can't see the disk, you could give Kroll Ontrack (Google for your country) a call and ask their advice. These guys are very good, when I needed them for a client, they discussed the problem over the phone and suggested what they thought might be the problem and the likely cost of a solution. You can then decide whether that cost is worth it to you. As I said, they aren't cheap but if the photographs are your wedding or your first born, it may be worth it to you.