accelerate.rb

  def self.accelerated_belongs_to(record)    
    klass = record.to_s.camelize.constantize    
    
    if !klass.respond_to?(:current)
      raise ArgumentError, "#{record} does not implement the current class method that is needed for accelerated_belongs_to."
    end
    
    self.belongs_to record    
    
    alias_method :"#{record}_without_acceleration", record
    
    define_method(record) do |*params|
      (klass.current && send(:"#{record}_id") == klass.current.id) ? klass.current : send(:"#{record}_without_acceleration", *params)      
    end
  end