I've been playing with a special effect. Let me know if you think I've got it right. It's a sort-of Predator cloaking effect. I'm pretty happy with it, as the first attempt was pretty much completely invisible and had to make the effect more 'visible' so viewers could tell it a 'special effect'.
Only a couple of seconds long and is about 500K.
If anyone likes it I'll be happy to write a tutorial on how I did it all. Warning though, it takes bloody ages!!! Hence only a couple of seconds of test footage.