It would be great if the currently selected buffers bookmarks as a group in the sidebar. Sometimes I consider breaking up a css file just for quick jumping but this would help.
For long pages it would be so muck easier to click a link in the sidebar that was appropriately name bookmark. I guess you'd need to be able to name booksmarks or display some the line text as the header.
Vote here http://sublimetext.userecho.com/feedback/23819-/