I'd asked the same question earlier today in a different post, and I'm very surprised that Storyline is so limited in it's ability to easily customize such basic features like volume control, or menu display. Although many basic controls can be assigned to custom buttons, there doesn't seem to be a trigger for volume control (or for displaying/hiding the menu). You should be able to assign any trigger to any Storyline control feature/function, that way be able to have a customized button/hotspot for it. I'm with you Allison---would be great to be able to customize those without having to recreate them.
Steve, Isn't there a problem with relying on a widget works only with Flash output in terms of devices/software that doesn't support Flash? Aren't there any other more generic widgets or add-ons for customizable controls (such as volume/vcr controls)?
All of this would be less of an issue if Storyline allowed you to fully customize the layout/size/position of any of their default controls---seems like such a basic idea.
I'll add my two cents as a feature request (thanks for the suggestion Ashley).