If you're like me, you don't have US$600 lying around to
purchase Photoshop CS2.
For those of you who do, turn away - what I'm about to tell you
might shock and amaze you. Or you'll simply think, "that program
must be a load of junk." Either way, with a few simple keystrokes -
www.gimp.org - you'll end up with the GIMP 2.2.13 (or 2.3.11 for developers) a
free, open source program similar to Photoshop.
When people say GIMP, you might think of someone who walks with
a limp, but GIMP stands for GNU Image Manipulation Program.
The GIMP started out with two students at Berkeley who released
a stable version, 0.54, in 1996. Ten years later, the GIMP is going
strong and hard, and it's putting up a fair fight against Photoshop
CS2.
The GIMP has its limitations. Seeing as how it's free, it won't
have as many features or tools or effects as Photoshop CS2.
To run the GIMP under Windows, you only need to download the
installation file and let it run.
For OS X, however, you need to install the X Windows system
(it originated with Linux, not Microsoft) and then download the
install file and run it. Along with X Windows system, you also need
OS X. The GIMP will not run under any classic version of the
Mac OS, and it's very unlikely that it ever will (I learned this
when trying to get it for Mac OS 9.2.2).
Using the GIMP can be a little confusing at times, especially if
you're used to other systems. A lot of tools in the GIMP are very
sensitive to use and need to be used with kid gloves when you start
out. Say you're trying to smudge over blemishes in a picture (and
not bother using iPhoto) - if you're not careful, you could end up
blurring the entire picture.
Some areas are very limited, like trying to take a picture and
rearrange it into words or another picture, for example. I tried to
rearrange the iDoom words into my own representation and failed
miserably, possibly because the program is still limited in many
ways - or more likely that I still don't know a thing about editing
images. 
Further Reading
