One thing missing from Mac OS X is a simple and free paint program, you know like that other OS has. But there are several free programs like this you can download. Seashore leads the pack by being both easy to install and use, but still having powerful features like layers support and good export options.
Skitch is a free tool that can be used to capture your screen and then draw on the image. You can also start with a blank image, photo or any file. You can export the result or upload it to the Skitch Web site to share.
The Mac doesn't come with any drawing tools. Fortunately, two free programs give you some basic ability to draw and edit images. Check out Paintbrush and Seashore for Mac in this excerpt from the MacMost.com Guide to Switching to the Mac.
Learn how to take a photo in iPhoto 09 and make a small square icon to use as your icon or avatar in social media networks like Twitter, Facebook and other blogs and forums throughout the Web.
Use the Preview application that comes with Mac OS X to cut out a person or object from a photo and make the rest transparent. You can use this to make better images for social network profiles, Pages documents or Keynote presentations.
Gary Rosenzweig and Eve Park take a look at two programs for the Mac that allow you to draw. The first is Eazy Draw, a vector drawing program. The second is Doozla, a drawing program for kids.