Pixen: A Free image editor for Mac

I am using Pixen for image editing on the Mac.  Like others that have written, I was surprised that no such program was included in the Mac OS.  I’ve just barely started using it but it so far it does what I need.  I was particularly impressed with the getting started wizard that took you through an overview of the program and  allowed you to set some program settings at the same time!  I model of what all programs should offer.  The only think I would recommend is showing a Page X of Y on each wizard page to let the user know how long it is.

Update:  Paintbrush is a nice alternative that emulates the Windows Paint program