I would like to comment on the use one space after a period at the end of a sentence. - sm

Over and over on these boards I read angry and disgruntled posts from MTs about how they feel it is only due to greed on the part of their MTSO, or due to some conspiracy carefully crafted by AHDI, that requires one space after a period at the end of a sentence. 

One period after the end of a sentence is not strictly an MT standard.   Everywhere in media, print journalism, and academia one space between sentences has become the norm.

This, for just one example, is copied/pasted directly from Grammar Girl's website.  The specific URL is below.  (Sorry for the bolding, it pasted that way and the html controls will not let me unbold it!)

Two Spaces After a Period--The Old Way

Here's the deal: Most typewriter fonts are what are called monospaced fonts. That means every character takes up the same amount of space. An "i" takes up as much space as an "m," for example. When using a monospaced font, where everything is the same width, it makes sense to type two spaces after a period at the end of a sentence to create a visual break. For that reason, people who learned to type on a typewriter were taught to put two spaces after a period at the end of a sentence. 

One Space After a Period--The New Way

But when you're typing on a computer, most fonts are proportional fonts, which means that characters are different widths. An "i" is more narrow than an "m," for example, and putting extra space between sentences doesn't do anything to improve readability.

Notice how in this example, the "i's" and "t" take up much less space in the proportional font than they do in the monospaced font.

Although how many spaces you use is ultimately a style choice, using one space is by far the most widely accepted and logical style. The Chicago Manual of Style (1), the AP Stylebook (2), and the Modern Language Association (3) all recommend using one space after a period at the end of a sentence.