Basically flex is invented for developing rich internet applications and adobe introduced flash concepts in flex and flex will run on flashplayer.. so indirectly u are working on flash environment... any u are asking for the perticular scenario...
Take one example i.e u have an application that is displaying several photos slide by slide in ur website. ( with some animations and other effects that are not available in flex).. at that time u can go for flash developing.. u need to develop that in flash and import that into ur flex application
visit ur Tour the flex web and there in flex4 we have some realtime scenarios where adobe already developed a dashbord to display the world map and the density of adobe site users.. they are using ibm ilogix for dashbord..they developed this components in flash and they have used that component in flex ...we dont have some animations that are available in flash and also u can develop some components in flash and import them into ur flex application as swc format.and u can use them in ur application
i think u got my point... for this u want have glance please go through the link below
there u have some dash board applications developed in flex and flash.. check it out ..
Thanks for the time taht was a nice explanation and also the site you pointed out is great , But are there any scenarios other than display of Maps where in these both technologies (Flash and Flex are used in)??
U can check out the nvidia website and some part of sonyericsson website .. presently they were not implemented in flex ..but i have seen it before they have deloped the sonyericsson website in flash and flex environment..grooveshark website..some of show cases are available that are developed in flex and u can go through that websites. those websites show u how can we use flash environment in flex