The obvious alternative to org-mode is planner-mode for Emacs. The great
advantage of both tools is the close integration with the rest of the
Emacs working environment (it is so much more than a great text and
programming editor): mail client (vm, wanderlust, gnus, notmuch,...), the
contact database (bbdb), and all the other great tools like doc-view,
anything, w3m etc. With these Emacs tools at hand, everything is nicely
cross linked or searchable (via moccur, tags or the trackerd - anything
Best of all: you need one set of keybindings, and never the mouse.