Lightroom is made for batch processing large numbers of images at once, good for pros who have a lot of photos from a wedding or other job to do quickly for a client. I think that's why some people spend the money for both LR and PS-CS3. You need CS3 for heavy image editing, but lightroom is faster for batch proccessing a lot of RAW files at once, at least on modern computers. Mine is old and LR is slower on it than CS3 is. Also, LR lets you catalog images, it helps you organize. I have been using iView Mediapro for a long time so I wasn't interesting in using LR for that, though I think it is probably good for organizing, I didn't really play with the features.