I saw these useful shortcuts posted by Bogdan:
Ctrl + Shift + End = marks the text up to the last line

Shift + F3 = changes the case of the selected text (from UPPERCASE to lowercase) AND TITLE!!

Shift + F5 = jumps to the last edited text (even after Word is restarted); pressed again, it will move between the last five edited bits of text

and want to add some more:

Ctrl + F6 = toggles open windows in Word 97

Ctrl + < = reduces font one point (you can hold it pressed to keep on reducing)

Ctrl + Shift + < = increases font one point (you can hold it pressed to keep on increasing)

Alt Gr + 4 = ~, useful for phonetics or Portuguese: /bõ:/, pão, Camões. Use as any other accent.

I hope they're useful to you.