DcBob over at Clan Plaid Hotline let us know that he typed into the ringtone composer of his cellphone a part of the Marathon 2 theme. His transcription is as follows:

8f2 8#d2 8f2 4#g2 8f2 8#g2 4#a2 8#a2 8#a2 8#g2 4#c3 4c3 8f2 8#d2 8f2 4#g2 8f2 8#g2 4#a2 8#a2 8#a2 8#g2 8#a2 8#g2 4#a2

My own cellphone doesn't have this feature, so I can't try it out, but if anyone does, let us know how this works out.