> One of the things I'd like to be able to do is capture a new TODO from a
> command line.  e.g.

I use the following code that I got from Jack Moffit
(http://www.metajack.im), that does more or less what you're looking
for, I think. Add the following block to your org configs. 

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

(defadvice capture-finalize (after delete-capture-frame activate)
  "Advise capture-finalize to close the frame if it is the capture frame"
  (if (equal "capture" (frame-parameter nil 'name))
      (delete-frame)))

(defadvice capture-destroy (after delete-capture-frame activate)
  "Advise capture-destroy to close the frame if it is the rememeber frame"
  (if (equal "capture" (frame-parameter nil 'name))
      (delete-frame)))

(defun make-capture-frame ()
  "Create a new frame and run org-capture."
  (interactive)
  (make-frame '((name . "capture")))
  (select-frame-by-name "capture")
  (delete-other-windows)
  (org-capture)
  )


;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

Then call emacs as follows: 

emacsclient -n -e '(make-capture-frame)'

Even better than calling from the command line in my experience is
triggering directly from your window manager, or something like
quicksliver if you use OS X... 

I hope this is a start.... 

-- 
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 garen@tychoish.com
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  http://www.cyborginstitute.com/
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