Mobile phone ring tone facilities have improved over the years, with the latest models playing back MP3 and WAV audio files. However back in the day, if you have a Nokia mobile phone you could insert the following Millennium Ring Tone into it's Nokia Composer facility. This probably still works on many modern phones that allow you to enter notes. 
Millennium Theme by Mark Snow (Nokia Ring Tone Format)
Tempo=60 4g2 16#f2 2d2 16e2 2.b2 16- 16b2 8.d3 2.e3 16#f3 8.e3 16b2 2.a2 4b2 2a2 4.d2 8e2 16#f2 2.a2 16- 16a2 8.b2 4.a2
8#f2 16#g2 2#c2 16b1 2.#c2 16b1 8.d2 2e2 4.g2 8#f2 16g2 2a2 2b2 1b2
Keys that should be pushed to program the ring tone on the Nokia Composer facility:
5*; 488#; 2999; 3888; 7(hold-down) 999; 0888; 7888; 2(hold-down) 9*; 3(hold-down) 99; 4888#; 3(hold-down) 9; 78**; 6(hold-down) 999; 78; 69; 2(hold-down) 8; 38; 48#; 6(hold-down) 999; 0888; 6888; 7(hold-down) 9; 6(hold-down) 9; 48#; 58#; 1999#; 7888**; 1(hold-down) 999*#; 7888**; 2(hold-down) 9*; 399; 5(hold-down) 8; 48#; 58; 6999; 7; 79;
Tempo=70 BPM
*NB: The ";" character is just a separator for reasons of displaying the key presses on this web page in a more readable format. There is no need to enter this into your phone!
Translation of the Ring tone to Nokia RTTL format:
Music:d=4,o=5,b=60:g,16f#,2d,16e,2b.,16p,16b,8d.6,2e.6,16f#6,8e.6,16b,2a.,b,2a, 4d.,8e,16f#,2a.,16p,16a,8b.,4a.,8f#,16g#,2c#,16b4,2c#.,16b4,8d.,2e,4g., 8f#,16g,2a,2b,1b
MIDI Format:
You can download the Millennium Theme Music in Midi Format below, the file size is 3KB.
Many thanks to "Takeshi" and CellNews.net.
Millennium Theme Music Composed by Mark Snow.
"MILLENNIUM", and all related characters are © Copyright, 1013 Productions & 20th Century Fox Television.
