Shortened version of unzip that doesn't create sparse arrays

underscore.js

@@ -506,16 +506,8 @@
   // `[['a',1],['b',2],['c',3]]` returns the array
   // [['a','b','c'],[1,2,3]].
   _.unzip = function(tuples) {
-      var results = [];
-      _.each(tuples, function (tuple, tupleIndex) {
-          _.each(tuple, function (value, itemIndex) {
-              if (results.length <= itemIndex) {
-                  results[itemIndex] = [];
-              }
-              results[itemIndex][tupleIndex] = value;
-          });
-      });
-      return results;
+      var maxLen = _.max(_.pluck(tuples, "length"))
+      return _.map(_.range(maxLen), _.bind(_.pluck, null, tuples));
   };
 
   // Converts lists into objects. Pass either a single array of `[key, value]`