Today, digital cameras, memory cards, and computers have replaced film, flash bulbs, and darkrooms. Tasks that used to take days can be done in hours—with superior results. Of course, you still need to take photos. The iPhone 4 has a 5-megapixel camera, and the iPad 2 has a camera as well. If that's not sufficient for your needs , you'll need to invest in a stand-alone digital camera. The good news is that you can take care of most of your photo editing needs with your iOS device and a few well-selected and inexpensive apps. Say goodbye to darkrooms, expensive equipment, and caustic chemicals. (Because of its larger display, the iPad is the best iOS platform for photo editing, and I tested these apps on my iPad.