Everyone that I talk to on a regular basis gets their own ringtone so I can know who's calling without even having to look at the phone.
Generic Ring:
America, Fuck Yeah
Beer
Born In The USA
Curb Your Enthusiasm
Dumb Pop Song
Full Metal Jacket
So Fresh, So Clean
Top Gun Theme
And all my SMS, MMS, emails, and voicemails get
Zelda Secret Noise
Each one has a specific meaning for the person it's associated with.