I recently had a smart media card go south, I don't know what happened to it, I just kept getting a card error message. Since I only have a mac with 10.3.8 (Panther) I was not able to reformat the card.
I have since installed 10.4 (Tiger) and the option to format or erase a disk in ms-dos format in Disk Utility has returned, I think it was present in 10.2 (Jaguar).
I reformatted the card via a USB card reader and then inserted the card into my camera (Toshiba PDR-71). It asked to reformat the card and I did so, successfully. So one card saved.
So if you are like me with only a mac and a bad card give it a try in Tiger, it may work.