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.
Creating an animated GIF from a video is easy if you have an app to do it. Learn how to use GIFBrewery to create a quick GIF from a video. You can view these GIFs in the Finder, or in a web browser. You can also share them and upload them to many web sites.
You can perform some basic and fun image editing using only the Preview app that comes with your Mac. You can cut out a part of one image and paste it into another. You can also crop and resize an image before exporting it to share it.
Learn how to use layers in Pixelmator. You can place one image on top of the other and then use masks to blend them. You can use a simple clipping mask to quickly reveal only part of an image. You can use a layer mask to create cool effects like blending two images together gradually.
Learn how to crop photos using Pixelmator and then resize and export them. You can also cut out a part of an image and trim it. Pixelmator has a variety of ways to modify a selection to create better cut outs.
TypeStyler is an old Mac graphics tool that has reappeared in the new Mac App Store. You can use it to create beautiful text complete with textures, 3D effects, curves and other elements. It is a handy tool if you need to create titles for projects.
Learn how to create transparent images for use in Pages, iMovie and other applications. You can cut out part of an image using the app Pixelmator and that part of the image becomes transparent and shows the items behind it.
While you can't add text or shapes to a photo in iPhoto, you can do it using either Pages or Preview. Pages allows you to add a variety of shapes and even other photos. Preview allows text and simple shapes.
Learn how to use Snow Leopard's Preview application to cut out backgrounds or objects in images and photos. Preview has a standard Lasso Selection tool, a Smart Lasso tool and an Instant Alpha tool that can be used for this purpose. You can use these semi-transparent images on top of other images, in documents or in iMovie.
Learn how to replace a folder or file's default icon with one from another file, or one you create in a graphics program. Find out how you can use a free graphics program to create your own icons and use them to make it easier to identify folders in the Finder.
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.