If you're running a production site, it's a good idea to record all exceptions which occur. See how to set up a notification system which does that in this episode.
Note: I forgot to mention, the exception_logger plugin requires will_paginate, so make sure you have that installed either through a plugin or gem.
Also I should have mentioned the importance of adding authorization to the controller so not everyone can access it. The README shows you how to do this.
gem install will_paginate
git clone git://github.com/ryanb/exception_logger.git vendor/plugins/exception_logger
script/generate exception_migration
rake db:migrate
# config/environments/development.rb
config.action_controller.consider_all_requests_local = false
# in controllers/application.rb
include ExceptionLoggable
private
def local_request?
false
end
# routes.rb
map.connect "logged_exceptions/:action/:id", :controller => "logged_exceptions"