Earlier today we released the Flex Ajax Bridge (FABridge) on Adobe Labs. With the FABridge you can make your ActionScript classes available to JavaScript without any additional coding.
For more information, checkout What Is the Flex Ajax Bridge?, which includes an overview and links to a ZIP download and sample application, and Ajax Client for Flex Data Services (ACFDS), a JavaScript library that will enable Ajax developers to access the messaging and data management capabilities of Flex Data Services directly from JavaScript. There is also a video demo of ACFDS available.
