mode-line-hack.el is a ModeLineConfiguration by JaeyounChung? will let you hide the ModeLine whenever there is only one Window displayed in the Frame. Information like buffer name and TextCursor position (Point) is put in the HeaderLine instead. This might be useful for vi refugees.
To completely remove the modeline from one buffer (buffer-specific) evaluate:
(setq mode-line-format nil)
and to make it affect all buffers evaluate:
(setq-default mode-line-format nil)