http://edwardhotchkiss.com/blog/2012/07/14/getting-spine.js-to-work-with-mongodb-and-object-ids/

models.js

/**
 * @application
 * @file /app/helpers/models.js
 **/

Spine.Model.extend({
  toJSON: function(){
    var attributes = this.attributes();
    attributes['id'] = attributes['_id'];
    return attributes;
  },
  fromJSON: function(objects) {
    var results;
    if (!objects) {
      return;
    };
    if (typeof objects === 'string') {
      objects = JSON.parse(objects);
    };
    if (isArray(objects)) {
      results = [];
      for (var i = 0; i < objects.length; i++) {
        var value = objects[i];
        value['id'] = value['_id'];
        results.push(new this(value));
      };
      return results;
    } else {
      return new this(objects);
    };
  }
});

/* EOF */