I happened across this rather nice spring physics library for Processing, so I thought I'd try making a simple cloth simulation to see what it was capable of. Turns out it's really easy to use and works exactly as advertised. I think it's time for a little more experimentation.

Instructions

Drag any of the vertices around to control the "cloth". Hold down the space bar while releasing the mouse button to "pin" the vertex.

Source

You can grab the source code for this if you really want to. You'll need the traer.physics library if you want to run it in PDE.