I wanted to view some KML files, so I tried to install GoogleEarth in BT 5 R3. My first attempt was a bust, so I thought I'd document how the successful install went.
First, you should update your aptitude manager with 'apt-get update'
Next, install lsb-core
'apt-get install lsb-core'
Next, install gdebi
'apt-get install gdebi'
Next, install the base googleearth-package
'apt-get install googleearth-package'
Now make the debian package to install
Lastly, install it with the package manager
'dpkg -i googleearth_6.0.3....deb'
You'll now have an icon for GoogleEarth in the Applications -> Internet menu! Enjoy!