Webcam as speakerphone?

My crappy headset finally died and I need to get a new one. But I don't care for wearing a headset. And I mostly used it for phone calls via Google Voice and didn't care for scrambling to get the damn thing on whenever the phone rang. So, I could just get a mic that sits on my desk. Or I could get a webcam if it's possible to use its mic for voice only when I need to. Then I could also use the cam for video conference calls instead of my laptop. Anyone know if that's possible? Specifically, I get a call via Google Voice on my desktop, I hit answer, and the mic on the webcam picks up the audio even though I'm not using video chat.

Yup, I do this from time to time and it works great. Obviously you should be looking for one with a better than average mic, and it turns out the Microsoft Lifecam that I got a while ago has an unexpectedly good mic.

Awesome! Thanks for the info. And thanks for the recommendation!