I've not used these plugins (so I'm not sure about the info)

zentest - launch test all time

redgreen - colors on console (useful for zentest)

filecolumns - upload files

acts_as_state_machine - máquina de estados

exception_notifier - mailer object and a default set of templates for sending email notifications when errors occur in a Rails application

-- HecPeAre - 04 Dec 2007