Notice of Predisposition: I hate W. Okay? Believe me. Ask anybody.
Disclaimer: I don't have any special talents regarding document forensics.
Right. The Boston Globe and 60 Minutes Bush national guard service stories were based on materials allegedly from the personal records of the now-deceased Colonel Jerry B. Killian. It seems quite obvious to me that the August 18th document is a crude forgery.
I say a crude forgery because it was done with MS Word using out-of-the-box defaults for font, font size, margins and other settings. If you type the text into Word (I did, look here) you get an identically-appearing result, minus the scrawled signatures and the (trivially simulated) photocopy/fax artifacts.1
The giveaways are:
- Alignment of the first character of the date line with the period in the first paragraph.
- All four line breaks in the first paragraph.
- Superscript "th" in "187th", fourth line, first paragraph. This is what you get with Word's default settings in the "Autocorrect Options..." menu dialog "Autoformat as you type" tab "Ordinals (1st) with superscript" setting.
- As was immediately observed, the whole damn memo was in a proportionately spaced font, pretty freaking good for a typewriter issued to an Air Force Reserve desk in 1973.2
Message to Democrats: Given the forger seems to be either very stupid or alternatively, hoping it will be detected, this could easily be a Republican dirty trick. DROP THE TOPIC, NOW
Update (9:20pm): Wow, there's a lot of stuff in the Blogosphere about this. The most convincing, showing an overlaid fax and Word reconstruction like mine is Little Green Footballs.
 Formatting details: Five tabs before typing the date line, three returns after. Double returns after "Memo", "Subject" lines, and each paragraph.
 Yeah, sure, the IBM Executive series typewriters. Give me a break.