Just yesterday my friend told me how one of his 2 GB SD cards got corrupted.  He tried to recover his pics and only one card reader was able to do it after many tries.    He's sending that card back to the manufacturer.  
For archiving data I'd use DVD, or DVD RAM, or just plain CDR, but my first choice would be an external eSATA Hard Drive which is blazing fast and can hold 500 GB.

"An Example is worth Ten Thousand Words"