Imagine you need to make a walk-through showing someone how to turn on a feature in Safari. Normally you would need a screen capturing app, a text editor, a image editor, and Safari running to get this done. Lots of switching back and forth, and lots of time later you have what you wanted. Enter ScreenSteps. It is smart enough to watch your clipboard for any screen grabs you make, and it enters them in a document. Just snap away, switch to ScreenSteps when you're done and there are all your shots waiting for you to type in some text. ScreenSteps also has some rudimentary image editing, and a host of graphics you can add to your images (to circle buttons and what have you).
Once you have this ScreenSteps document you now need a way to share it with folks. You can export it either as a PDF, as valid HTML (with templates that you can customize), or share it on ScreenStep's hosted service.
ScreenSteps comes in two flavors: regular goes for $39.95 while the Pro version that lets you create an index that lets you group together a number of ScreenSteps documents will set you back $59.95 (a full comparison can be found here).