Gnome sensors-applet is aimed at showing hardware temperatures into a pretty deskbar applet.

Current stable version available in source flavor is 1.8.2 whereas the one shipped with Ubuntu gutsy 7.10 is only 1.7.12, several changes have occurred between these two versions, most notably:
- support for new sensors
- new tango icons

Furthermore the version available from Ubuntu repositories does not support nVidia thermal sensors.

Sebastian (comment #6) has provided a precompiled package here: http://www.wains.be/pub/sensors-applet_2.2.1-1_i386.deb Thanks!

Here is a quick how-to for quickly building an updated package of this applet with nVidia thermal sensors support:

(commands in bold)

1) download latest sources from http://sensors-applet.sourceforge.net/index.php?content=source

2) unpack them via tar xzf sensors-applet*.tar.gz

3) install some required extra packages and their dependencies via apt: sudo apt-get install libgnome2-dev libpanelappletmm-2.6-dev libgtk2.0-dev mesa-common-dev build-essential checkinstall

4) download latest nvidia-settings sources form here ftp://download.nvidia.com/XFree86/nvidia-settings/ or via apt apt-get source nvidia-settings

5) build the libNVCtrl library
cd nvidia-settings*/src/libXNVCtrl
xmkmf
make clean
make

6) install libNVCtrl and related headers
sudo cp *.h /usr/local/include/
sudo cp *.a /usr/local/lib

7) enter sensors-applet folder cd sensors-applet*
run ./configure --prefix=/usr --with-nvidia

8 ) now, if you just want to install them run make and then sudo make install

whereas if you want to build a deb package run sudo checkinstall and follow the step by step instructions.

9) after having installed the applet you have to rightclick on the deskbar and choose add to panel then select sensors applet. Finally you have to configure the sensors by rightclicking on the applet icon and selecting properties.

enjoy a thermal monitoring station on your computer!!

PS: average high warning values are:

for Hard Disk drives ~55°C
for CPU ~85°C
for nVidia GPU ~110°C