Feb 23, 2006 - Layout Enhancements in Flex 2
Center Canvas, Invisible Objects, and Absolute positioning...

Manish Jethani summarizes some great enhancemnts regarding:

Center Canvas
- An object can be anchored to the edges of its parent
- Anrhcoring an object to the center of its parent

Invisible Objects
- Removing objects from the layout used to be difficult
- Now is easy with the includeInLayout attribute

Absolute positioning in Application and Panel
- App and Panel containers support absolute positioning of child objects

Full Article at:
http://mannu.livejournal.com/319589.html