It would be fantastic if we could drop a small unintrusive icon into our code and then name it, and have a panel that shows us a list of all of them. Click it, it takes you right to that icon.
With longer processes a lot of time is spent scrolling through code to find the part you were working on, jumping back and forth, etc.
It could possibly be added to the Outline panel, a way to mark items in the outline and then a button that shows only the items marked.