Widgets are simply Flash applications.
You configure which widgets you want to show on a chumby from the chumby.com website - each chumby has a unique "key" that the lets the server know what widgets are supposed to show on that chumby.
The widgets are not actually stored on the chumby itself - they are pulled on demand from the serve, although they may be cached. At the moment, the widgets cycle at a default rate of 30 seconds each, although that is configurable on the server.
There is a "control panel" interface, which is brought up by squeezing the chumby, that allows the user to modify various settings on the device, as well as manually advance the rotation of widgets.
The device is hackable to run Linux programs that have been compiled for this processor, but as there is no window manager such as Gnome or KDE (indeed, not even X), you can't run most desktop applications unmodified. At this point, we will not be supporting the downloading of Linux applications through our service.
There is currently no microphone in the device, however, one can be added either through the USB or by a hardware hack.
We do not support a browser, and there is no standard text input method.
In general, the chumby is not designed to be a strongly interactive device, such as a PDA or computer. Anyone that wants to change that is invited to use the freely downloadable tools and hack it to do whatever they want.