Lefteris,
No, not out of the box. You would have to modify code to add this capability.
Don't forget to click the Mark as answer check on this post and to click the top arrow (promote).
Follow the steps as shown in the below graphic:
It seems the upcoming new version of the FLEX API has support for overlays. Horray!
http://resourcesbeta.arcgis.com/en/help/flex-api/samples/index.html#/Adding_Graphics/01nq00000012000...