The question of how to set up global variables in a Flex application came up on the Flex Components list recently, and as it comes up every so often, I figured I would blog one of the answers.
This is actually very easy. Just define a public variable within your main application class, like so:
Check out this nice Flex 2 Color Picker that Tinic Uro put together. (Tinic is one of the engineers on the player team).
You can view the example here (source included).
Darron Schall has made a post explaining why he has been getting excited about the Flex Framework.
You can view the entire post here.