I kind of want to disagree with Kai (while still appreciating all the support work he is doing on this forum!) – I know that you can plug in multiple Logitech Quickcams – they get different id’s somehow and are all distinct devices at the USB, and video driver level. Unfortunately TWAIN has no concept of multiple units of the same device, so all QuickCams on a system appear as a single TWAIN device. At least, without hacking such as stoops (above) is talking about. Within the QuickCam TWAIN dialog you can select which camera you want to use, but there is no way to control that through TWAIN.