Microsoft LifeCam VX-5000 1.3MP Webcam for $24.99 shipped. It has a CMOS image sensor that captures video at up to 640 x 480 resolution; still-image at 1.3MP (1280 x 960), and a built-in unidirectional microphone with acoustic noise cancellation as well as automatic adjustment for low-light conditions. As a comparison, Best Buy has it for $49.
Originally posted earlier, this is just a friendly reminder.