A collection of photos taken at the classic trail from South Rim down to Colorado river and then to Phantom Ranch. It was done in one day, in December 2011 and return was from exactly the same way.
The complete gallery: http://photoexplore.gr/?portfolio=grand-canyon
You can see the GPS track and some tips here: http://www.everytrail.com/view_trip.php?trip_id=1379290