Ok, I am crazy about Conky, editing Conky code is a great way to learn a bit about programming and your hardware.
Conky is a free, light-weight system monitor for X, that displays any information on your desktop. Conky is licensed under the GPL and runs on Linux and BSD.
Conky Hardcore http://conkyhardcore.com/
The Conky Links http://conkyhardcore.com/beginners/conky-links/
The Conky PitStop http://old-cps-do-not-use.wikidot.com/
Many thanks to code from Conky by Hanna, The Conky Queen!