Covers the lens and most of the microphone on the round Microsoft Lifecam. It isn't sound-proof, but muffles sound-pickup significantly for at least improved privacy.

The original design file I created is published on Tinkercad.

It doesn't need supports when printed lens side down. You can use pretty large layer heights to make it print even quicker. I used wood-fill filament and concentric for the first layer (in Cura) for a more interesting look.