Alternatives to Photoshop

Fotoflexer.com
A free online image editing software. You can add animation to your photos, cut a person out of the background, crop, resize, and lots more! There is even a neat feature for creating posters! A great little tool for basic image editing techniques.
Gimp.org
An open source image manipulation program. Great tool for photo retouching, image composition, and image authoring.
Inkscape.org"
An Open Source vector graphics editor, with capabilities similar to Illustrator, CorelDraw, or Xara X, using the W3C standard Scalable Vector Graphics (SVG) file format."
Pixlr.com
For photoediting