My original post on echo cancellation: Echo Cancellation Issue
We've been waiting for Adobe to add echo cancellation to Flash. It finally arrives in Flash 10.3, for the desktop PC only (no mobile devices). It's not in AIR yet.
I've done some testing on Windows (Firefox), and it seems to work okay. But sometimes there are still echoes, and I have to manually adjust the microphone gain to find the sweet spot (between 6 and 8 on my system). To adjust your microphone gain setting, make sure your webcam is in the Main window, then use buttons 3 and 4. You should see "Microphone Gain" value displayed next to the buttons when they are pressed. It's not perfect, but we're getting there.
So if you are interested in testing it out, just download and install Flash 10.3 for your web browser, and when you turn on the microphone (button 9), you should see "Enhanced Microphone 1" displayed next to the button. If you see just "Microphone 1", then echo cancellation is not supported for some reason (drop me a note). Note: According to the Adobe forums, Flash 10.3 may introduce some graphics problems, so I suggest install it on a test system if possible.
Mobile devices must wait for an AIR update that support this feature. Or go the hardware route, use a bluetooth headset, or speakerphone:
Samsung HF1000 Speakerphone $10 after rebate (04/01/2011 -
(I have no affiliation with the above site, just found a good deal on it)