cheat sheets.

These things have all been deprecated.  Some of them may not exist at all in
Rails 2.0.  You've been warned!

  @params        
    Use params[] instead.
  @session       
    Use session[] instead.
  @flash         
    Use flash[] instead.
  @request       
    Use request[] instead.
  @env           
    Use env[] instead.
  find_all       
    Use find(:all) instead.
  find_first     
    Use find(:first) instead.
  render_partial 
    Use render :partial instead.
  push_with_attributes 
    Use has_many :through instead.

These things are not technically deprecated, but stay away.
  components      
    Use of components are frowned upon.
  paginate :model 
    The default paginator is slow. Writing your own may be faster.