Those three javascript functions are all you need on the web page to dynamically add html to your page without having to hit the refresh button. Those functions open whatever file on the server you tell them and whatever that file would have output to the screen on its own is captured in the response variable. The file on the other end has typically been php or asp so you could maybe dynamically grab data from a database. But that file could just as easily be html. The response doesn't have to be formatted html either. It's a string in a variable when it gets back to the ajax function. If it was well-formed html you might use it like this... document.GetElementByID("dynamic_div").innerHTML = response. Maybe the response looks like this... A=1|B=2|C=3 and you'd write some javascript to parse it into individual variables. I like the latter for the arduino so I can keep it's code as lean as possible.
My issue is with webduino as it stands now. For whatever reason, when the AJAX functions go looking for the file on the arduino webserver, it can't find it. One thing I haven't tried yet is using a prefix on the arduino side. Something like 192.168.3.111/arduino/arduino.html?GET_VARIABLES.
I have a Logitech F510 Rumble Pad. It's able to emulate an XBox controller. I've written a simple ActiveX object based on the XNA Framework that's able to interact with the controller. There are 21 different variables on it (buttons, joystick axes) and I can put them all in a query string.
If webduino isn't ultimately my answer, I'm going to look at sockets.io.js next.
donjuevo