> Would you be satisfied with changing the background color for >spaces? Step 1:
Ah, that's an idea. Just "/ " to search for spaces (assumes highlighting's turned on), and they'll all be highlighted. He wants to turn off highlighting, just "/qqq" or something. Else maybe tweak the font to change space to · or something. Thing is, change the font to something else, and that goes away, and he'd have to tweak the font for that as well. Eg, if he's using Lucida console 10pt, make a copy of the font, rename to something else ("Lucidaspace" or whatever), edit the font to change the space char, then when you want visispaces, just font your way to that. Want invisispaces again, change back to the normal Lucida font.