I think that number is per address. Not sure what the failure modes are, so the test you mention may not be a good one (e.g., failure mode may be that the value is there for a few minutes, or hours, etc).
SD has an SPI interface mode, so you can use an SD card as an SPI flash device. This acts like a chunk of flash, no FAT filesystem and pop it in a computer type support unless you write it.
There are also external flash devices from various manufacturers.
If you're worried about device failure due to excessive write cycles, check out the Ramtron FRAM devices. Their claim is more than 1014 write cycles. At a glance price is comparable to other flash devices. I'm currently looking at them because of the speed and instant writes - no need to wait between writes.
-j