It is sometimes useful to align a particular line in your buffer in your Emacs window. Rather than moving the cursor and recentering the buffer around your cursor, this is more easily done if you can simply scroll the text. Add the following code to your .emacs file and use Ctrl-, and Ctrl-. to scroll up or down one line at a time.
(global-set-key [?\C-.] 'scroll-down-one-line)
(global-set-key [?\C-,] 'scroll-up-one-line)