I have not put effort estimates on my tasks for a long time.

Tonight, I was playing chess and saw a "notify" message come up on my
Linux box that <some task> should be finished by now.

Wow - I never knew org-mode had that built-in!  I ran a git-blame on the org-source
code [1] and it's been a long time, right?  I haven't tested whether it sends a Growl notification
on OSX but that's really cool!

(It was kinda creepy at first, though)

Thanks,
--Nate

[1] https://github.com/emacs-mirror/emacs/blame/f8284f1e408b38e6a3c0e2a1d5a465fefac6800a/lisp/org/org-clock.el#L698