For my photo essay, I took pictures documenting my morning commute on Metra trains. I then toned and adjusted the pictures in Photoshop to make them look as good as they could. I did this because raw photo files don't always look as presentable as they could, and Photoshop allows you to bring out a photos full potential.
I adjusted the brightness and contrast in the pictures so they would accurately convey the lighting conditions of the early morning sunlight. I also adjusted the hue and saturation of the colors to give them the warmer feel that the early morning sunlight lends to a scene.
With the photo inside the train, I did similar brightness, contrast and color adjustments in order to emphasize the artificial lighting inside the train and how it makes the color scheme inside the train look a bit cooler than the outdoor scenes with natural lighting.
For the crowd scenes, I also had to adjust the sharpness of the photos in order to reduce motion blur.
EDIT 11/1/10:
I forgot to show an original, raw photo for comparison, so here's the original shot of the train coming in:
Like I said above, I lowered the brightness and increased the contrast in the toned version to better convey the early morning sunlight and the warm colors that it gives to everything. This adjustment, along with some minor color tweking with hue and saturation, let the bright red on the front of the train and the vivid colors of the commuters' clothing stand out more in comparison to the more muted, dull colors of the original raw file.