I think I know how to do what you want to do. Here is a link to a wiki article that goes into excruciating detail.

http://wiki.developerforce.com/index.php/Using_Browser_Technologies_in_Visualforce_-_Part_1

The basics are, create a javascript function in your VF page to accept the text from flex. In Flex, use ExternalInterface to call that function passing the text. From the JS function, call an actionFunction defined by in the VF page. This will post the text to your VF page controller.

You’ll have to include the boiler plate JS code to get an object reference to the executing swc, which is well documented on the Adobe Developer site.

Cheers.

Wanted to see if you have any idea about how we can communicate with salesforce controllers from a swc file.I want to some how pass the information from my flex app to a salesforce controller,similar to sending information to a javascript from a swc file.Is it possible at all?

For example I have a small text area in flex and I want to pass the text from that text area to a controller that will accept that text.Lets say I have the controller that will accept string values how do i invoke it from the flex app(assuming that it is deployed in visual force page for simplicity).

Any pointers are appreciated.