Youtube today introduced a new feature that allows publishers to invite others to annotate their videos .
If your reader is likely to be used in an academic or professional setting , then being able to highlight , save and annotate passages is incredibly useful .
There are any number of services that offer the ability to annotate web pages or share finds with friends .
The teacher will be able to digitally annotate the performance and send it back to the student .
The world 's largest online retailer said that from later this year customers would be able to borrow e-books from libraries and read and annotate them on a kindle or any other device to which users have downloaded a kindle app .