After some websurfing, finally found how to change my Dell Mini 9 resolution.
The normal 1024×600 screen resolution is hard to do much development work on.
With Fedora 12, editting the XORG.CONF file does not seem to work. Instead, you have to use XRANDR.
In my case, use
xrandr –fb 1600×1000 –output LVDS1 –panning 1600×1000 –scale 1×1
Voila! Mouse will allow me to pan & move around my larger virtual screen size.
If you want your display to be configured when you “login” to Fedora, add the above line into your ~/.bash_profile or ~/.bash_rc configuration file.
This file is run at user login.