Occasionally, when I am writing something in either Pages or Keynote, I use the word "may" (not meaning the month), but Pages / Keynote automatically reformats it to "May." Since I believe it to be more of a hassle to change "May" to "may," especially since I rarely write may meaning the month, I wanted to get rid of the automatic 'correction' that Keynote and Pages make.
For Keynote, control-click on the Keynote application (in the iWork '06 folder) and choose Show Package Contents. When the new window opens, navigate into Contents -> Frameworks -> SFWordProcessing.framework -> Versions -> A -> Resources -> English.lproj, and then open the file named AutoCorrect.plist. If you use Property List Editor (default), then click on the triangle for Root, then the triangle for capitalizationDictionary, and change whichever values you want.
For Pages, do the same Show Package Contents bit, then navigate to Contents -> Frameworks -> SFWordProcessing.framework -> Versions -> A -> Resources -> English.lproj, and again open AutoCorrect.plist. Then proceed as you did with the Keynote file. In both cases, remember to save your changes.
Note that many of the text replacements are in the file AutoCorrect.plist, whereas most of the symbol replacements (e.g. replacing ... with an ellipse, or (c) with ©) are, for Pages, part of the preferences file in your preferences folder -- because these items are editable within Pages. Keynote, however, lacks the auto-correction tab in its preferences. Thus, Keynote's preferences file does not contain these corrections.
It's curious that Apple opted to keep some entries hidden from the preferences in Pages, and bury them in a property list file deep in the application. All the corrections, in my opinion, should be visible from within Pages' and Keynote's preferences.
[robg adds: You'll only see this effect if you've enabled Fix capitalization in the Auto-Correction tab of Pages' preferences. Keynote, as far as I can tell, has no GUI method of enabling automatic capitalization fixes -- so I'm not sure why they bothered to include the table. On both of my machines, Keynote 3 doesn't do any capitalization fixes. I did, however, find a way to enable this feature, and that's covered in this hint.]
Mac OS X Hints
http://hints.macworld.com/article.php?story=20060410165705216