gistfile1.rb

# Hash form:
{
  :current_user => "CurrentUser.current_user"
}

# Discovery form with inverted app structure:
module Injectables
  def current_user(session)
    User.find(:id => session['current_user_id'])
  end
end

# A whole class seems like overkill. Then again, we've talked about
# injectables without fixed names. That's scary, though, because we
# can't ensure no clashes.