Grabbed the following from Yahoo. A little outside the 3D realm.
The Talk n' Play software enables up to four people to simultaneously
conference and play games over the Internet with no additional fees or added
phone connection charges. The Talk n' Play conference works with virtually any
online game and, with the included headset, allows `hands-free' voice
communication so players can keep pace with the game action. Talk n' Play
supports simultaneous microphone and speaker operation and utilizes Microsoft's
DirectSound technology allowing the user to hear the conference as well as the
game audio