We (my wife and I) shoot animals, which means we do take LOT of pictures. Our motto is, basically, hold the continuos shutter button down and let the critter do it's thing. We will typically shoot, in a couple days, as many as eight thousand shots, to be narrowed down to 100 or less keepers. Even at this, we still shoot best quality JPEG or RAW (in tougher light situations), but never both. Most of the images are instantly dumped in pre-processing, so the space issue isn't really important. You know when you blow through two batteries in a D80 in 5 hours that you have shot a BUNCH of pictures (they are good for over 2K shots per battery).