On my old laptop I tried using them before, but the poor thing couldn’t handle it.
Now with my new laptop I decided to give it another go.
Using compiz-fusion you can put these screenlets on a special ‘widget layer’, which you can summon by pressing a keyboard key. Whenever you need some information or need to make a small note, you press that keyboard key and the widget layer is displayed. Pressing the same key again and the widgets disappear.
There’s a nice screenlet that displays some sensor information, CPU and HDD temperatures. However, my laptop has another sensor on the graphics card that shows the GPU temperature. I just had to have this added to the screenlet.
I made a modified version of the Temperature2 script to generate a screenlet for nvidia GPU temperature. You’ll need the proprietary nvidia drivers installed and access to the ‘nvidia-settings’ utility. Download the file and place it in the ~/.screenlets/Temperature2/ directory, overwriting the old file.
Update: My modifications are now included into version 0.4 of Temperature2. You can get it at screenlets.org