Check out this blog http://www.solicall.com/blog/?p=27 - for a discussion on echo cancellation for browser-based applications.

Yes - it works very well. You can easily try SoliCall Pro. It dramatically reduces echo/feedback

You might want to try SoliCall. It will do AEC for you (either on client or the server side) and is available today.

Dear Adobe Employees,Since it looks like this issue is still open, please allow me to suggest a simple solution that you can easily & quickly implemet.All you need to do is simply to supply API to access the audio (i.e. read frames of audio signal and write them back). We will do the rest from there...