Aneesoft Free Image Editor is an extremely simple graphics editor that has just enough functionality to be useful.
The program is compact, and installs quickly. There are no hassles, it won't try to install the Ask toolbar, the setup program just copies the necessary files into place (the entire installation requires under 6MB of hard drive space) and then launches Free Image Editor for you.
The interface is unusual, with no menus, no hidden functions - everything you can do is accessed from a few buttons at the top of the screen. So to begin you'll probably click New > Load image, and open a picture. The program only supports the main formats, but the ability to open ICO files is a useful addition.
Once you selected an image then you're able to rotate and crop it, or perhaps add a text caption. This latter option allows you to select the opacity of your text, as well as the font, its colour, size, style and more.
Clicking the Effects button reveals a host of other filters and options. So you can tweak brightness, contrast and gamma, flip the image horizontally or vertically, apply filters like posterization, solarization, threshold, video, emboss, halftone and so on.
And when you're happy, the image can be saved (though only as a BMP, JPG or PNG file).
There are obviously all kinds of limitations here. You can't select and work on part of an image, there's no support for layers, you don't get any automatic photo fixes, there's not even a resize option.
If you're just looking for something really simple, though, Aneesoft Free Image Editor may still be useful. It's easy to use and will help you complete (very) basic editing tasks with the minimum of hassle.