Not sure how well known this is but I discovered this gem a while back and a conversation on min-maxing brought it to mind. Thought I'd share.
Falling Objects
Just as characters take damage when they fall more than 10 feet, so too do they take damage when they are hit by falling objects.
Objects that fall upon characters deal damage based on their weight and the distance they have fallen.
For each 200 pounds of an object’s weight, the object deals 1d6 points of damage, provided it falls at least 10 feet. Distance also comes into play, adding an additional 1d6 points of damage for every 10-foot increment it falls beyond the first (to a maximum of 20d6 points of damage).
For each additional increment an object falls, it deals an additional 1d6 points of damage.
Heavy things falling hurts. Cool. Now that we've established that, how can we use that to our advantage?
The best way I've discovered so far is Wildshaping from a bird to a beast, which allows you to instantly crush the opponent.
Rhino: 6000 lbs - 30d6 + distance damage, level 8 Wildshape - 105 average damage
Triceratops: 20000 lbs - 100d6 + distance damage, level 16 Wildshape
Any of you guys have other ideas?