If your primary reason is to post on the net you only need a resolution of 640x480 (307,200) pixels at 72 dots per inch. Your lowest resolution cameras will give that to you but the higher cameras, say a 2.1 megapixel (millions of pixels) 1280x1640 - cost as low as $299. The camera is more versatile and is not limited to flat art. If you're going to 4 color process printing, then scanning might be the prefered method. But then again, all the photos in Campiglia/Wells book are from a digital camera.

A scanner may give you better quality but if I'm shooting multiple items, the camera is much easier to set up, shoot, and download into my computer. i can fire off about 10 chips on the camera in the same time as gangin them on the scanner and cropping, etc. I've got samples of both. Now both these images are purposely large so you CAN see the difference. But you certainly can't get your kids to sit still on a scanner. ;-)