map()

$(SELECTOR).map()

 <input id="name" value="yahoo" />
 <input id="url" value="http://www.yahoo.co.jp/" />
 
 var output = $("input").map(function(){
      return $(this).val();
 }).get().join(" ");

$.map()

 var people = [
  { name: "taro", age: 10 },
  { name: "jiro", age: 8 }
 ];
 var name_list= $.map(people, function(person){
      return person.name
    });

参考

http://api.jquery.com/map/