As I said in another post Flash 8 authoring tool allows for the creation of templates for mobile devices.
The templates can do a couple of thing:
1) create a template application (basically set correct width/height for the device, set the correct publishing settings and prepopulate the FLA)
2) configure the FlashLite emulator (look&feel, capabilities,buttons,etc.)

This blog explains how to create such a template and has an example for the iRiver u10:
http://www.scottjanousek.com/blog/?p=180

Since I have it installed for my u10, I made a copy and changed to work for the Chumby.
You can download a preliminary version from here:
http://www.aromatic.org/chumby/Chumby.zip

This is very preliminary! It's a copy of the u10, with the u10 screen and the u10 buttons. It also says that your Chumby can do anything the u10 does (but as a FlashLite 2.0 device).

To use it, download the zip file and expand it in C:/Program Files/Macromedia/Flash 8.
Then open the Flash authoring tool, create a new file from a template and pick the template  "chumby_chumby" from the "Global Phones" category.

You should get a new stage with a 320x240 gray box and you should be able to add stuff to it, save it and test it.
If you are lucky you'll get the emulator with a screen that looks like... the IRiver u10 (but it should say something like "non official chumby template".

Now I need a real Chumby to test what it can really do and "fix" the template accordingly

Enjoy!

-- Raffaele