Here is a great video that comprehensively describes the architecture of Flex and Apollo and provides some very good implementation examples. This was delivered by James Ward (Technical Evangelist at Adobe) at a Google presentation.http://video.google.com/googleplayer.swf?docId=-1156113143758326102&hl=enIn addition to this you could see some examples at Web Spiders site at https://www.webspiders.com/flex and https://www.webspiders.com/flex/shoppingcartAll copyright for the above video belongs to the respective owners.