At least on Macs (other OSs, I wouldn’t know), you find two distinct space characters: the “normal” space, which is rendered by simply pressing the Space Bar, and the “hard” space (aka. “fixed space”, or “non-breaking space”), rendered by pressing Alt/Opt + Space Bar. This is extremely useful for the proper layout of a text (try and picture the text “2 Gb”, where “2” is at the end of a line and “Gb” at the beginning of the next one: a hard space “glues” the two elements.) In certain languages (French comes to my mind), it’s a feature you can’t live without.
Well, if I press Alt/Opt + Space Bar when, say, composing/editing a mail, it doesn’t do anything — not even a “normal” space. I can’t think of any application on the Mac where you can’t digit a hard space, so I believe that it shouldn’t be too difficult to implement in eMC.