I presented this jsHack in the Learn Office Hours today. It allows an admin to select a list of courses (check the boxes), then open the Enrollments, Grades, Course Files, and/or Course Entry Point for each course in a new tab in the browser with the push of a button. Very useful when performing bulk operations.
This is one of the oldest jsHacks that we ever wrote, so the code is very quaint. Could probably be improved, but is still useful.