Echo without headset, are there solutions?

Hello,

When I am chatting with Red5 webcam chat software, there is a high level of echo when I don't have any headphone on my head. I thought that this was something inevitable, but when I use Skype I have exacly the same problem, but only for 2 seconds!

I think that Skype has some kind of filter that automatically starts at that moment.

I am using already a method in Java to reduce echo and I have checked the option "Reduce Echo" in the Adobe Flash Player settings, but this is absolutely not enough.

Someone has any experience with this?

Regards,
Vincent