For my next foray into mobile development with Flex and AIR, I'm trying an application with the default UI of the BlackBerry Tablet, the QNX api.
Encouraged by my success with that last project, I applied some of the same techniques. I changed some of the colors, positions and layouts. I'm still not happy with it, but the failings are mine, and not QNX's.
Flex rocks. Not having to spend time laying out stuff, add child objects to the stage, and generally being able to style components directly through an attribute or CSS is a huge productivity boost.
Finally I learned that by default when you run a QNX app on your system you don't have the fonts to make it look good. Even if you install it, it still won't look good. I had to manually add the font as a text format to all of my controls. Annoying, but worth it. The text is listed as something like BBSans, but it is actually called DejaVu and is freely available. Thanks to Kevin Hoyt for pointing that out.