feature request: tooltip-show-at-point

[Masatake YAMATO <jet@gyve.org>]

With tooltip I'd like to show the eldoc's output at the point, not 
at the echo area. I wrote a patch for the purpose.
The main part of the patch is the following function:

(require 'avoid)
(defun eldoc-tooltip (text)
  (let* ((P (mouse-avoidance-point-position))
	 (frame (car P))
	 (x (cadr P))
	 (y (cddr P))
	 (oP (mouse-position))
	 (oframe (car oP))
	 (ox     (cadr oP))
	 (oy     (cddr oP)))
    (set-mouse-position frame x y)
    (tooltip-show text)
    (set-mouse-position oframe ox oy)))
(eldoc-tooltip "California, here I am.")

This function works, however too slow to follow the point motion 
in real time. How do you think to provide a built-in function which
show the tooltip at point?

Regards
Masatake YAMATO