A few days ago I stumbled upon Swiz, which bills itself as the "brutally simple micro-architecture for Rich Internet Application development with Adobe Flex." If the term micro-architecture or the buzzword Rich Internet Application haven't scared you off yet, read on, because it really is a lovely little framework.
Why are some things just much harder than they need to be? Finding a current, easy-to-use data source for populating a country selection box, for example.
Note that your document class in Flash projects should extend org.gaeswf.flash.BaseApplication and your Application MXML in Flex should be of type org.gaeswf.flex.BaseApplication (if none of this makes any sense to you, see my Flex 3 Code Behind Quick Start.)
The updates in a nutshell: