You can jump to any line in a buffer with
Hit the shortcut and then the letter of a line in the popup and you’ll go there.
You can get back quickly with
Note: as of this writing the function on this key is
but it will be changing to
avy-goto-line in the next release.
Update February 2016:
SPC l is now the new layouts engine. This
functionality is now located at
SPC y. Thanks Caolite O’Connor for the catch!