AJAX Scroller: Controlling multiple areas on one page

Is it possible to modify this plugin to scroll over not just one area, but two areas on the same page, with the same "previous" or "next" button?

You mean 2 items at once? Not currently.

Hmm. There's no way to add a JS listener to somewhere else on the page and load new content upon, say, completion of the scroll transition? Is there any way to hack this module to get it to do something like moving 2 items at once? I really need that functionality... how much do you charge for custom development of this module?

It's not possible currently but it's a feature I planned. If you need it badly please contact me on mail and we can arrange something on custom job basis.