So, I've had skitch in my apps folder for months and never used it. Finally, it just occured to me that it's the perfect tool for marking up this image. I open the image in Skitch but I can't figure out how to do the simplest (and maybe one of the most common) thing -- select, copy, and paste part of the image. In almost any graphics program, that's usually the default operation. Yeah, I know -- Skitch isn't exactly a graphics program...still looking....