The Page Title
Notice that the drawbacks mean that if an attempt to present emdash or endash fails (which happens more than often), the display can be very confusing to the reader. Since the difference between hyphen and the dashes is usually esthetic or stylistic only, the risk involved in the attempts to use emdash or endash in HTML is rather big as compared with the possible gain.
For completeness, there is yet another method one could think of: Use an image. Something like <IMG SRC="emdash.gif" ALT="-">. The basic problem is that you cannot know the size of the font in which your text will be presented, so you cannot know how large the image and the dash in it should be (in pixels). Thus, you cannot specify the actual width of the symbol. (Notice that even by using the FONT element you cannot dictate the font size in pixels.)