If the card reader will not show up at all on my desktop when I insert the corrupted card- how do I run a recovery program? Any suggestions. I am on a mac, and it is a 4gb SanDisk extreme IV card. A friend borrowed the camera and used her Dad's card reader and the images were not there, and then when she put it back in the camera- the images were gone. I am assuming they are still on the card, but cannot figure out how to get them off. This was for her Grandpa's 90th birthday party and we would really love to be able to recover them.

I immediately thought of all you OSP smarties!

The first thing I'd try is one of the file recovery programs you get with high-end CF cards, like the Lexar UDMA 300x ones. If it won't see it, then I'd try Disk Warrior -- that's fixed this kind of problem more than anything. I've been using it for more than 10 years and nothing comes close to fixing disk directory issues (which is what this sounds like).

I try to run it at least once a month on all the hard drives to keep them in good order.

if the images are not that important.. then try several options that you find on here..

if they are a wedding or something really important, stop everything and take the card to a professional, every application/program etc can write over the images, then they are really gone

When I've bought Sandisk cards it comes with a CD with a program called DataRecovery. Never used it though.
I also bought Photorescue a long time ago and it saved my corrupted images.

Here's Photorescue
http://versiontracker.com/dyn/moreinfo/macosx/17201

The recovery software will find the ones that wont mount as long as they are connected to the computer.