There are kits that can clean the memory slot ...
Compact Flash Slot Cleaning Kit (p/n XAX-Cleaner) =================================================

http://store.yahoo.com/memx/20102.html
Secure Digital & Multimedia Card Slot Cleaning Kit (p/n Cleaner-MMC/SD) =======================================================================

http://store.yahoo.com/memx/20101.html

The manufacturer might be able to provide software that recovers data from
a "failed" memory card -- that software might also be able to either reformat
the card or even mark unusable areas. 

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MGD