Last week I stumbled across OrbLog, a weblog which offers a few awesome Windows Sidebar gadgets. Allthough the blog is in German, the gadgets are available in English. Check out this article for more info.

NVIDIA GPU Temp – Sidebar Gadget
Displays the temperature and the type of graphiccard
Download
 

Top Five - Sidebar Gadget
Shows the top five processes that use up most of the processor load or memory usage.
Download
 

Quad / Dual Core Usage - Sidebar Gadget
Displays Processor / core utilization and temperature
Download

For all or additional gadgets from OrbLog visit this OrbLog website:
blog.orbmu2k.de/