If you're doing a lot of post-processing, you want to shoot in RAW. Besides giving you more detailed (and probably better) color data, it also acts a a digital negative, as most software is non-destructive to RAW, meaning it works with the data of the file, but creates a separate file when you finish the processing. With JPEG you usually have to work with a duplicate of the original image if you want to maintain the original as well. It is a lot more data (I can only fit about 150-175 RAW files on my 2GB cards vs. almost 500 JPEGs), but pretty much required if you want to do post-processing.