Microphone array beamforming is a subject that I have given a lot of my attention to over the last ten years or so. Simply put, microphone arrays are the electronic equivalent of a parabolic dish (those big plexiglass dishes that they use at football games to hear the sounds of contact and shouted calls on the field). Mic arrays let you hear sounds in a particular direction, possibly even far away, depending on the system design and environmental conditions.
As you might guess, I was pleased to learn last year that Microsoft will be building support for small arrays into Vista, its next generation version of Windows. The idea is that laptop and tablet PC manufacturers will embed small (4 element) mic arrays into their products to focus on the user's voice and cut down on noise so that VOIP, speech recognition, and other voice-based applications can work better. They also included an automatic echo canceller (AEC) to kill feedback loops between the microphone and loudspeaker in the laptop or tablet PC. These feedback loops are familiar to all who remember assemblies in gradeschool when the principal got his microphone too close to the loudspeaker and everyone got an earful of a high-pitched screeching tone! This would also happen on a VOIP call if the AEC wasn't included, so that is a good thing.
Anyway, I came across a introductory video clip from Microsoft Research on the topic of mic arrays and what is coming out in Vista. It can be found here. Note for Firefox users: you may need to use "Open in IE Tab" for the plug-in to play the video correctly.
(Image source: Microsoft Research - a four element, uniformly spaced, linear microphone array with USB cable)