[pbohun]

This page was put together very well. It has interactive illustrations when needed (not excessive), and the explanations were informative yet concise. I also like how it brings up other uses of quadtrees, such as for images. This encouraged me to think about how they might be used elsewhere.

[rustystump]

I used quad trees in a janky fractal compression schema starting big and only moving small if a feature couldnt be represented in the larger space. It kinda worked. And then you add motion into the mix with oct trees. Love this stuff.