SanDisk has unveiled their very first write-once memory card, called the WORM (Write Once Read Many) SD card. It's not really aimed for consumer use, but rather is geared towards industries where unalterable content is important, such as electronic voting, court testimony, and police investigations.

SanDisk makes the claim that there is "no physical way to alter or delete individual recorded files." They should have added "yet" to that statement because I'm pretty sure hackers would love to have a go at it and prove their statements wrong.

The WORM SD card touts a 100-year archive life when kept under appropriate storage conditions. For the time being the card is only available in the 128MB size, but larger capacity WORM SD cards will be out in the near future.

Unfortunately pricing hasn't been revealed, and you'll need to inquire to find out just how much something like this will run you.