Stop! Go back and re-read the subhead above—at least 2–3 times—then let it sink in before continuing.
The sentence above illustrates the proper use of the hyphen and the two main types of dashes. They are not the same, and must not be confused with each other. In some fancy fonts the difference is more than just the width—hyphens have a distinct serif. If you don’t know the rules already, let’s review them. First, though, a definition:
An “**em**” is a unit of measurement defined as the point size of the font—12 point type uses a 12 point “em.” An “**en**” is one-half of an “em.”
Via Jeffrey Zeldman Presents: The Daily Report [1], A List Apart: The Trouble With EM 'n EN [2]
So it made sense to use double hyphens (–) instead of em dashes and double primes (") instead of quotation marks. In any case, those workarounds were already familiar to anyone who’d grown up with typewriters, and readers adapted to ascii-only typography during the early days of the Internet when usenet, email, and the web all shared the same primitive markup and text display.
These days, standards-compliant browsers can handle entity names, and even Netscape 4.x can manage numeric entity codes—but why should you care? After all, using the technically correct punctuation marks would mean a dozen new entities to be memorized and a lineup of well-meaning but under-informed editors and teammates to win over—and retrofitting any significant amount of copy is always a hassle.
Also via Jeffrey Zeldman Presents: The Daily Report [3], A List Apart: Typography Matters [4]
It may seem strange that a programmer would care about typography, but it's not unknown—Donald Knuth [5] took 10 years off writing The Art of Computer Programming [6] to write the computer typographic system, TeX [7].
So I wrote some code to translate some of the more egrarious hacks I've been using to get what I want, and converted over using the proper characters that are available. And yes, I checked the the Usual Suspects [8] (Lynx, Netscape, Mozilla and Microsoft IE) and they all support the characters (well, Lynx as best as it can) required, so that's that.
[1] http://www.zeldman.com/coming.html
[2] http://www.alistapart.com/stories/emen/
[3] http://www.zeldman.com/coming.html
[4] http://www.alistapart.com/stories/typography/
[5] http://www-cs-faculty.stanford.edu/~knuth/
[6] http://www-cs-faculty.stanford.edu/~knuth/taocp.html