gistfile1.rb

RAILS 3.0.7

ruby-1.9.2-p136 :006 > c = Category.new(:title => "test")
 => #<Category id: nil, title: "test", created_at: nil, updated_at: nil> 
ruby-1.9.2-p136 :007 > c.new_record?
 => true 
ruby-1.9.2-p136 :008 > c.update_attribute(:title, "change me")
 => true 
ruby-1.9.2-p136 :009 > c.new_record?
 => false 

ruby-1.9.2-p136 :010 > c = Category.new(:title => "test")
 => #<Category id: nil, title: "test", created_at: nil, updated_at: nil> 
ruby-1.9.2-p136 :011 > c.new_record?
 => true 
ruby-1.9.2-p136 :012 > c.update_attributes(:title => '123')
 => true 
ruby-1.9.2-p136 :013 > c.new_record?
 => false