Have you checked the USB Notebook Mouse Internet Phone from Targus? Apart from mouse functioning it can double up as a voip phone. You even don't need to have a separate headset or microphone as the software available with it would solve the problem. Since nobody would like to put the phone to the ear for making calls all you need to do is press the scroll wheel and you can start enjoying calls with the speakerphone feature.

This internet phone works in both phone and mouse mode. While in mouse mode it functions like a standard three button USB optical mouse and whenever any call comes it automatically gets into the phone mode. You can either put the mouse to your ear or use the speakerphone option. It is compatible with Google, MSN, Skype, Yahoo and Vonage. It also has an integrated built in microphone, headphone jack, speakerphone and a built in independent sound chip with volume control so that you can enjoy a smooth voice. It is available for $49.99.

They also have a USB Internet Phone with keypad which is a flip phone and comes along with a built in sound chip, microphone and volume control on one side and a compact keyboard on the other end which can be used for inputting data and execution of commands. This keypad phone can be availed for $59.99.