from subbu
I learnt a tip from an eight-year old today 
.
I used to click up/down arrows to change values of a numeric tile - force of
habit. Just go click-click-click.
A simpler way to change is to hold the left (red) button down when the pointer
hovers above the arrows and move the mouse up and down.
from jerome peace
I played.
Turns out it gets better.
Just holding the mouse down over the arrow will cause it to repeat incrementing.
Moving the arrow up (once pressed over a button) makes it act like a vertical slider for the value.
This is funny when used for the x position but the y position works just as if you were holding the morph.
from takashi
I stole this feature from Pure Data.
I'm glad you found it!