The recommended headset model (i.e. headphones with microphone) is:
Logitech Clear Chat Style
Also the following headsets showed good results:
ClearChat PC Wireless (helps to suppress echo)
Logitech USB Desktop Microphone - Mikrophon (good sound, but bad echo cancellation)
Note for Mac OS X users: The build-in microphone normally has quite good quality and echo cancellation, so Mac OS X users often do not even require a headset.
Speakerphones
When several people participate from the same location, we recommend using the following speakerphone models:
Phoenix Audio Quattro2 USB Speakerphone MT301 (a single microphone + speakers can be used even with 20-30 people sitting in a room)
Phoenix DUET Executive
Jabra SPEAK410
Plantronics MCD 100M
Integrated Lenovo 3000 n100
Konftel 300
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