This thought is dedicated to you, <a href="http://4-ch.net/dqn/kareha.pl/1331675820/640">Mr. >>640 of another thread</a>.

Let the double hyphen approximation die. It's ugly, unless automatically replaced (e.g. in MS Word).

People have to be taught about the importance of Alt+0151 and Alt+0150 (the em dash and the en dash). IMHO, the en dash should be used for transition to the em dash, because it's both just a bit longer than the hyphen, and round numbers are easier to remember for most people.

What the world actually needs is a typographic layout with all less commonly used symbols accessible via AltGr+ combinations (with labels printed on the keyboard).

I call for a special aa/dqn layout with SJIS symbols placed in a comfortable Dvorak-like style.