Verlet integration (actionscript 3), in 9 minutes!
The first time I heard about Verlets was about 10 years ago I think, when I was working on a C++ program building a dynamic animated bridge, at that time all documents and resources I found about Verlets were really confusing and at the end I gave up on it (sometimes people explain simple things in the most complicated way). Last year 2009 in flash on the beach (Brighton, UK) when I was attending the session of Keith Peters, he came with some really good ideas about how to implement the “Verlet Integration” in flash using actionscript 3 in a very, very easy way that makes my imagination fly.