You might try foremost
. It's basically a forensics tool that lets you recover certain filetypes. You'll have to mount the drive on another machine or try to use a live CD. But I was able to recover my parents digital photo collection and all their word documents from a drive that got formatted by a virus in Windows.
If they're REALLY important, it's better to take the drive out of the machine and take it to an expert... The biggest thing is to not use the drive anymore until you recover the files because files aren't really deleted, just the address to the file is deleted. So the OS says "this is open space" and might accidentally overwrite the file (although this still might be recoverable).