Is it possible to change the voice of the “say” command?

Question

Is it possible to change the voice that Mac OS X uses for the say command? How?

Answer 1

By default it uses the System Voice set in the Text to Speech page of the Speech panel of System Preferences. Otherwise, you can use the -v option with one of the named voices:

say -v Zarvox "found it in the man page"
say -v Agnes "found it in the man page"

Answer 2

man say yields this

  -v voice, --voice=voice
       Specify the voice to be used. Default is the voice selected in
       System Preferences.