There is such a good webcam in universe that acts as a "USB Video Class" (UVC - video USB standart interface) - the logitech webcam 9000. UVC offer unified interface allowing to control it or grab a picture from it by any UVC-driver. You need one universal driver and you support all the UVC devices (webcams, video-cameras, video-grabbing-cards etc). For example, in linux - if you have UVC driver - you don't need to think about specific webcam driver for UVC webcam. UVC has unified way that webcam transmit its awailable resolutions and other capabilities, so i see 1600x1200 resolution without any problem.

I wonder if windows 7 has UVC. I mean "universal UVC" (-; It says "USB Video Class", but doesn't give resolutions larger than 640x480 and webcam's controls, like 'sharpness', 'focus' and other as linux's driver does...