Sorry, these are the controls:

ALT + mouse = rotate
ALT + CTRL + Mouse = zoom in/out
ALT + SHIFT + Mouse = pan

I have used the scale trick now alot, it's really great.
One suggestion though (sorry :-)
When scaling a very large object to a small object, the large objects can obstruct the view alot when lining up the origin points.
It would be handy to select 2 origin points. One for the correctly scaled model and the other for the one that needs to be scaled WITHOUT them being in the same x,y,z point.
That way i can move the "wrong" object out of my view and scale more eaily.