Flip Effect - NOT PAGE FLIP

I’ve searched for tutorials on this but I can’t seem to find anything on how to create simple flip effects. I’m not sure if it’s some other program than flash or just someone with awesome animation skills - here are a few pages I found on Monster that has this effect.

This looks like its done straight in flash:

This looks more like some kind of 3d program:

Either way, I’d like to learn - Any Ideas?