http://www.gurulib.com/_scripts/barcode/gurulib_barcode.html

Note: webcam are not designed to work as barcode readers, so this flash component won't work as fast as the barcode readers in walmart. You need to bring the barcode very near to the webcam and should have a steady hand. The barcode capture video below will give you an approximate idea how close you need to bring the barcode to the webcam. The flash code tries to capture a good barcode picture with white bars and black bars clearly visible. If your hands are shaky, the webcam blurs the image. Following method worked for us consistently.