I do not have enough to buy and even keep upgrading the Photoshop every year. So I have found GIMP to be a good alternative for me. Though I am not a designer, yet, I do have to use photo editing when I am slicing and making websites or even emails from the designs sent by my clients. Unfortunately, I do not know if there is a plugin for GIMP that would import Photoshop too. So I have a portable version of Photoshop too with me though it is much older (CS3) and was given to me by a client who had many PSDs to be sliced.