Happy to, and Schlereth (sp?) covered this on ESPN, he would know, being an ex-offensive lineman (which may be telling about the Broncos, but that's an argument for another time). You take the tape into the locker room at half time, you look at the signals alongside the stills of the pre-snap and post-snap polaroids that every team gets of every play, and you figure out when this hand signal goes in, these are the adjustments they make, so now we know what we need to do to counter that. In the second half, you have a jump on what the defense is doing. That's one example, I'm sure there are more that I'm not aware of.