- Save each screenshot with a unique name
- Save the screenshot into ~/Pictures/
This AppleScript will prompt you (as does Shift-Command-4) to select some area to be captured. When captured, it will be saved to your user's Pictures folder, with the name as "Screenshot YYYY-MM-DD_hour.minute.second.png," and opened in Preview.app.
[robg adds: This previous hint used a script to grab a shot and open it immediately. This version adds the unique naming convention and changes the save location, and the script worked as described in my testing.]

