How'd they do that?

Sometimes I get questions pointing to an example of web, game, or video animation, asking, "How'd they do that?" Sometimes I even get it on my own tutorials, when my final result has a few bonus features that weren't covered as part of the main lesson. Right here, right now, is your chance to ask "How'd they do that?" and get an explanation. Post your question and your example to this blog, ask "how'd they do that," and I'll break down a step by step of how it was accomplished - even if I have to figure it out myself, first.