I have a new product, which allows using of a standard PC headsets or cell phone headsets with Cisco IP phones. They work with Cisco 7940, 7960 and 7970 IP phones as well as with newer models. Don't spend hundreds on specialized headsets - get your hands free with fraction of price.

http://www.headsetadapter.com
http://www.ciscoheadsetadapter.com
http://www.nortelheadsetadapter.com
http://www.headset-adapter.com

PS. We carry headset adapters for 3Com, Nortel and Norstar phones as well.