>> Topic.find(:all, :select => "id")
=> [#<Topic id: 3>, #<Topic id: 4>]
>> Topic.find([3,4])
=> [#<Topic id: 3, forum_id: 1, subject: "Newer Topics", user_id: 3, created_at: "2008-03-12 12:10:54", locked: false, views: 1, sticky: false>, #<Topic id: 4, forum_id: 1, subject: "Old Topic", user_id: 3, created_at: "2008-03-12 12:11:08", locked: false, views: 2, sticky: false>]
>>