[FelixFelicis]

>>Like they used to have to use Polaroids (some places anyhow) to ensure the pictures weren’t altered at some point.<<

Interesting, I’ve wondered about that. I’m no forensic expert, but I don’t know how you’d ever be able to tell a good PhotoShop job from the real thing. Present-day technology would’ve made Winston Smith’s job way easier.

[gtk]

Higher end digital cameras can create a checksum for a image in the camera and record it in the original image file. Devices such as:
http://www.canon.co.jp/imaging/osk/osk-e3/index.html
can then determine if the file has been altered.

The AP and other media should require it from their photographers.

[MediaMole]

Canon makes a device that adds a cryptographic number to each photo taken for evidence. If the photo is altered, it will no longer match.

http://www.dpreview.com/news/0401/04012903canondvke2.asp