Yesterday I accidentally learned that you can reposition the closed captions on YouTube videos. I waa at the Smartboard talking about how the cursor and my finger were a couple of inches apart, and I accidentally dragged the captions of a YouTube video that we were watching.
On iOS you can also move up and down between lines and select text with the spacebar (hold space, tap on keyboard somewhere else with another finger, drag space to select).
Neat for ios users!