GIMP (GNU Image Manipulation Program) is an amazing replacement for Photoshop, and can do all the same basic stuff. If you have photos that need to be edited, this is the program you should use. It is dear to me, as I previously taught a class in multimedia design, and this was the tool we used to teach photo editing (the text is still online, only slightly out of date!). 90% of the time I open it, I just use it to crop down a photo, but even for simple things like that, it is a breeze to use.
FLOSSing for lent 8/40