New to Moodle 2.6, Mary Cooch demonstrates how teachers can annotate and markup PDF submissions which students have made to assignments. This is a handy feature which, if implemented correctly (so that students submit the right file type) could drastically cut down on downloading and uploading files with markup and improve the overall level of feedback students are able to see directly in Moodle. Pretty slick.
Read more about the feature at http://docs.moodle.org/26/en/Using_Assignment#Annotating_PDF_files
Check out the video here or below: http://www.youtube.com/watch?v=MgsA-9qMBdY