Your "students" will prolly find this page and links + downloads from it useful, when they start to explore beyond twelve note equal temperament.
Can you explain exactly what contexts you use other tonalities? I have Toby Twinning's true pitched vocal CD which is very interesting to listen to. Are you or others using subtle non-equal temprement scales in pop or folk songs, or is this more of classical atonal or "ethnic" (arabic, chinese, etc) music? If you modulate during the middle of a song, then do you change tunings so that the pitches in that key are corrected?