Well I think you can buy photoshop CS (still relevant and common) for around a $100 or less now. If you can't afford it and still want it, you can go to the adobe page, download the free trial, find a serial/key gen on a torrent/crack site and enter it via the phone way. You don't actually have to call, the option is there for folks who don't want to use or don't have the internet. The idea is you call, they give you a serial, you pay for it, then enter it in. However, if you already have a serial or key you can just paste it in, and you should be all set. Otherwise, as wackdeafboy mentioned, there is GIMP which although it doesn't have as many options or is as good it is a free alternative. You can still do most of what you'll need to do unless you're big on graphic design. Then I'd recommend going for Photoshop.
If you'd prefer a legal alternative you can go to Online image editor pixlr free - fix photos direct in your browser I use it if I need a quick image resize and I'm not on one of my computers.
