The other option would be to place the drive in a functioning mac system and get some data recovery tools for mac osx.
Hiren's is primarily aimed at PC's and Linux file systems, but you may have some luck with it. If I remember correctly there should be at least two partitions on the drive, one is used by the system and is typically not seen by the users and the other will be the larger and house the data and OS. Since mac osx uses it's own file system that is typically not easy to view and read under other operating systems I would consider using some of the hard drive recovery tools found in Hiren's Boot CD to see if you can examine the drive structure and possibly the data itself.
