Temperature sensors in the Gnome panel

Most recent harddisks (with "S.M.A.R.T." technology) have a temperature sensor. Typically the CPU and the motherboard have one as well.

(all steps as root):

• install the following packages:
  yum install lm_sensors
  yum install gnome-applet-sensors
  yum install hddtemp
• run:
  sensors-detect
• run system-config-services, and enable the services hddtemp and lm_sensors. Start both daemons as well, and save changes
  (run yum install system-config-services if you don't have it installed).
• edit the file /etc/sysconfig/hddtemp to read: HDDTEMP_OPTIONS="/dev/hda"
  (you can of course put a different drive number, or more than one)
• right-click your Gnome panel, select "Add to panel", and pick the "Hardware Sensors Monitor"
• right-click the sensors applet that now appears, and select "Preferences": here you can pick the sensors you'd like to see, select Celsius/Fahrenheit, etc.