I'm looking for a Mac OS X program to recover images from a corrupted memory card.
I found File Juicer. It costs €12.95, but does the trick.
You can use the GPL program PhotoRec, which is a command line tool but with a good how-to on their web.
I haven't tried it myself, but I've had lots of success using the sibling TestDisk to recover FAT32 filesystems from external drives which weren't ejected under MacOSX before unplugging the USB drive.
Before recovery, plugging these drives would make Finder ask if I wanted to format them, but after using TestDisk their contents were accessible again.
I highly recommend PhotoRescue. The website isn't the prettiest but the program worked exceptionally well. Even though the card had been formatted twice all the photos were recovered.
I've had cause to use EXIF Untrasher. It's obviously not 100% pefect for a corrupted card, but I was pleased with the results.
If none of the cheaper options work, you might try Data Rescue 3.
Klix is specifically designed for recovering images from corrupted memory cards.It can be bought standalone, but through 10/31 it is also part of the MacPromo Security Bundle http://macpromo.com/apps.php which includes lots of utilities - TechTool Pro, antivirus, and others - 10 apps tptal.
$50 MediaRecover and $90 FileSalvage have both worked well for me in the past. Both are very slow, but get the job done. FileSalvage helped me recover 45,000 images after my iPhoto drive was erased. While neither is free, both are much cheaper than paying for Data Recovery Services (which once charged me $2500 to recover 40 gig of data).