One of the great videos from 360|Flex is Advanced ActionScript APIs by Jacob Wright. A lot of cool information about Proxy class and using custom metadata. Will definitely be useful even for experienced AS3 developers.

It doesn’t play from the site for me, but plays fine with Adobe Media Player.

Just not to forget how to make mxmlc and task save my custom metadata.

<target name="compile.test" >
 <mxmlc file="${source.dir}/TestsLauncher.mxml" output="${bin.dir}/tests/TestsRunner.swf" keep-generated-actionscript="false">
 <load-config filename="${FLEX_HOME}/frameworks/flex-config.xml"/>
 <source-path path-element="${FLEX_HOME}/frameworks" />
 <source-path path-element="${source.dir}" />
 <compiler.library-path dir="${libs.dir}" append="true" >
 <include name="fluint.swc" />
 <include name="alcon.swc" />
 </compiler.library-path>
 <keep-as3-metadata name="Meta1"/>
 <keep-as3-metadata name="Meta2"/>
 </mxmlc>
 </target>