Grab key scrolling

[Follower]

>> On Mon, 2007-04-16 at 16:42 +0200, Marco Pesenti Gritti wrote:
>>> Hello,
>>>
>>> we have the grab key on the keyboard which, when pressed, should
>>> activate the scrolling mode. It should work like this:
>>>
>>> 1 The user press the grab key on the keyboard.
>>> 2 The scrollbars of the current view are highlighted.
>>> 3 Movements on the trackpad (both resistive and not resistive)  
>>> scrolls
>>> the view. The mouse pointer is "locked" and does not change position.
I couldn't find any discussion about the origin of the grab key 
anywhere. I'm asking here as no-one knew on IRC and there was interest 
from others on the topic.

What advantage does one or more grab keys have over something like 
two-finger trackpad scrolling a'la Apple laptops?

One reason suggested was that the existing trackpads may not support 
two-finger operation, is this the case?

 From a personal experience point of view: there were utilities for 
older Apple laptops that turned "enter" or "function" keys into a 
similar key to enable trackpad scrolling before the more recent models 
supported the two-finger style. The latter--to me--is a much more 
elegant solution. (Two-finger scroll would also enable us to rename the 
grab key the "high five" key and use it for something else. :-) )

--Phil.