Bookmarks

Clicking the line number would add a bookmark to that line (visible by highlighting the line number somehow). Then a keyboard shortcut or popup window (maybe a couple icons added to the Line Number and Column number window?) would be used for navigating to First, Previous, Next, or Last bookmark (or just Previous and Next if there is not enough screen for four buttons). These icons could be hidden if there are no bookmarks in the open file. Clicking on the line number of a bookmarked line would remove the bookmark from the line.