Strangely, I know of at least one major federal agency that uses proportional fonts in official letters, but still insists upon using two spaces.
Two. You’ll get my extra space when you pry it out of my cold, dead hand.
Yes, you can. 
And if the original author puts a smiley after each sentence, you can globally delete those as well. 
Doesn’t mean it isn’t annoying.
It seems that I’ll get it rather more easily than that, actually.
(Mods: I know there’s a rule against editing quotes, but this is purely for comedic purposes.)
The article is correct. Two spaces are appropriate only when using monospace fonts.
This is why HTML ignores all extra whitespace after the first space, BTW. Nothing amuses me more than seeing some n00b web guru typing multiple spaces after his sentences only to have them rendered (literally) moot.
I was never taught how to type - I sort of figured it out myself (it’s not as if the keys don’t have letters on them). Using two spaces after a period never occurred to me. Seems like a waste of effort.
One space. What is *up *with you old fogeys and two spaces? Do you ring up the pharmacy on your rotary phone via a landline so you can make sure Ethel still carries those Little Liver Pills you take to keep away the palsy and the cattarh?
Come, join us here in the 21st century. It’s nice, I promise.
I learned 2. It’s a hard habit to break, so I’ll just keep using 2.
Why, you little punk! I’d smack you but I might wrench my shoulder.
shakes fist ineffectually
[Moderating]
This is just a reminder that altering quotes while retaining the attribution is against the rules even for comedic purposes. However, since your edit is invisible (which is part of the point) I won’t even make this a note.
Colibri
Moderator
TWO spaces. I like it. It’s perfect. One is too goddam few, and three would be extremely absurd foolishness.
Okay, I’ll bite: WHY do you think it’s “too goddamn few” spaces to just have one? Does it make the text less readable for you? Or is it just muscle memory as you type, as Barkis and a few others seem to be implying?
To reinforce the point that Mr. Excellent was making:
The following sentences have one, two, and three spaces after the period respectively:
“Two. You’ll get my extra space when you pry it out of my cold, dead hand.”
“Two. You’ll get my extra space when you pry it out of my cold, dead hand.”
“Two. You’ll get my extra space when you pry it out of my cold, dead hand.”
On the screen, the spacing appears identical regardless of how many spaces you put after the period. So those of you who continue to include two spaces are simply typing additional characters that don’t have any visible effect on your screen text.
I mean, go ahead if the force of habit is that strong, but you should be aware it’s pointless.
Yeah, but it’s an extra step and kind of annoying.
I use 2 but really believe one is correct, but when I try to use one in a long work of any kind, it becomes filled with both one and two because it is automatic to use 2.
One. Two spaces looks odd, like someone randomly sprinkled extra white space throughout their writing.
When people submit stories to the archives I host, step one of cleaning up the documents is always to have word replace all double spaces with single spaces.
Did you check the 1959 edition?
I think I originally learned that two spaces is correct. But during high school I was fortunate enough to find and read a book called The PC is Not a Typewriter, which explained that one space is correct for proportional fonts. Had some other good tips too, like not mixing serif and sans-serif fonts in the same document.
Let’s leave the department of Agriculture out of it.
Don’t we have this discussion every couple of months.
One space. One space!!! I learned two in typewriting class, but that was in the late 80s/early 90s for monospaced fonts. On a proportionally spaced font, you are supposed to use a single space.
Actually, typographers have been using a single space in typeset materials since before there even were rotary phones.
My typing teacher in high school in the 70s taught us to use two spaces on a typewriter, but pointed out that we’d only use one if we ever worked professionally in layout, typesetting, graphic design, or any other field that worked with type.
One space has been the universally-correct answer since typewriters were replaced with word processors. I have a macro on every system I use that removes multiple spaces after punctuation. I didn’t worry about it too much when I was editor of a content-based website (as pointed out above, the Web removes multiple spaces automatically), but that macro was the first thing used on every document I received when I was a newspaper editor.
Assuming Word 2007, you can select the Word Round Button, click Word Options, click Proofing, click Writing Style: Settings, and for Spaces required between sentences choose one of “don’t check”, “1”, or “2”.