It's safe to define your own 'id' method - using .id to get the object 
id is deprecated.

irb(main):001:0> Object.new.id
(irb):1: warning: Object#id will be deprecated; use Object#object_id
=> 24272204
irb(main):002:0> RUBY_VERSION
=> "1.8.4"
irb(main):003:0>

Dan Manges