Really? While I'm somewhat fond of Skitch, some of us find the UX rather confusing. The menu's were cluttered, and for the most part does not operate on common design patterns.

For example, nearly all image apps allow your to draw a box to crop. Skitch re-invents the wheel, and asks the user to learn their method: Dragging the inside border of the inner canvas. Yup.. actually had use Google to figure it out :/