hddtemp will give you the temperature of your PATA, SATA or SCSI hard drive by reading Self-Monitoring Analysis and Reporting Technology (S.M.A.R.T.) information (on drives that support this feature). Only modern hard drives have a temperature sensor.
Author: Emmanuel Varagnat <hddtemp@guzu.net> Homepage: http://www.guzu.net/linux/hddtemp.php