From Prosoft Engineering:
Data Rescue is the best Mac Hard Drive Recovery Software available today. Data Recovery for your Mac hard drive doesn't get any easier. Try the free demo to see if this Mac recovery software works before you buy! Do you have a corrupt hard drive or one that no longer mounts? Are other tools failing to even recognize your bad drive? Do you need to recover files that have been deleted? Data Rescue 3 is the best digital data recovery software on the market for recovering files from a problem hard drive or that have been previously deleted. Data Rescue 3 works when other tools fail. Data Rescue 3 is also completely safe to use since it does not attempt any risky repairs to the drive it's scanning. This is the safest, most powerful software to recover your hard drive. Data Rescue 3 is the same software used by many data recovery services. You will need to save your recovered files to either an internal or external hard drive (USB or FireWire), removable media device (such as a Zip or MO) or a networked drive. An optional emergency bootable DVD is available.
What's new in this version:
Added Mac OS X 10.8 Mountain Lion compatibility
Added a newly designed application icon
Added support for recovering MIDI audio files
Added date to JPEG file names for those that contain EXIF metadata.
Added an "Open With" contextual menu for scan results.