Just to announce although a bit late for April, but I’ve recently wrote two articles for JSMag. I highly recommend JSMag to any JavaScript developers who may be reading this.
My first article in April details with using on-demand JavaScript loaded with ExtJS – http://www.jsmag.com/main.issues.description/id=31/
The second article, for May details implementing client-side caching of JavaScript – http://www.jsmag.com/main.issues.description/id=32/