With regards to the hand tattoo image, I've pulled out the individual frames where things pop up, (there's 4 to be precise) but I don't know of any possible photo editing technique that will allow us to separate the message from the picture itself. Playing with the colour levels of the photo just adjusts the entire picture and the characters are as lost as they were before.
The hand tattoo photo doesn't move as fast as the other pictures that pan though, so Xav's idea of a programme that shows you just the pixels that have changed between one photo and another might allow us to isolate the individual pixels that pop up, and thus see the hidden message. But, does anyone know of any programme like this? Even though they appear the same colour to the human eye, there must be a difference in each individual pixel when they pop up.
EDIT: Having played it over and over again, I'm pretty sure what is appearing is actually the numbers "8, 2, 9, 1" in corners of the hand. I believe they're written in this font:
