Take a look at the graphics part of the GoogleAPI reference. It says that loadImage takes either a string, or the responseStream property of an XMLHttp. By XMLHttp, I assume it means XMLHttpRequest.
My problem is that I can’t find documentation for this field (the responseStream field) anywhere. I’ve had no luck googling it (ironc), it’s not in ‘JavaScript: The Definitive Guide’… yet these gadgets that use it seem to work.
This post says that responseStream seems to not be accessible from a browser’s XMLHttpRequest. From whose is it, then? Is it just a Google Desktop thing?
Not at all, IIRC it was originally developed by Microsoft and has been part of IE since v5.0 (not sure about other browsers).
See the XMLHttpRequest at W3C page or Google answer.
EDIT: Finally found the article I was reading: MSDN > MSXML 2.0