TechRadar checked out this screen capture tool for Mac OS X, it has an odball interface but is efficient.

"Skitch is an oddball. For a start, the interface doesn't resemble any other Mac app. However, for grabbing content, annotating it and then sharing or saving it, Skitch really does the business. You can capture images from your Mac's camera, drag it over to Skitch, or take a grab of the entire screen or a selection. However, content can only have the most basic of edits (crop and resize), but you can overlay all manner of annotations using Skitch's intuitive and non-destructive tools (which in themselves are also fine for composing quick, simple diagrams)."



Link: Techradar