A Juggler's Dilemma

Handling modern Javascript, and all its Ajax goodness, is often like juggling. You throw up a bunch of Ajax requests into the air, and then entertain the crowd with other means while you wait to catch the response.

Download this Node.JS program and run it to get started.

It is supposed to do a simple thing: download some images and zip them up into an archive for you. Why doesn't it?