I'm running Skype and other voice chat apps on a Lenovo ThinkPad W500 without a headset; I'm using only the laptop's built-in mic and speakers.
According to the people I speak with, the audio quality is perfect, even when I turn my head away from the PC. I've other apps, e.g. Oovoo and it's similarly good.
My past experiences have always been horrible - a feedback loop caused by the speaker sound getting picked up from the mic, low audio volume, etc. I thought Skype might be doing some fancy schmancy noise reduction magic but as I said above, the quality is very good even when using other apps.
I'm curious why the quality of my audio (as heard by the other person) isn't horrible in this configuration?