After installation, you need to manually start Google Desktop. However, after you reboot your system or log in to your X-session, Google Desktop will start automatically.
You can start Google Desktop by choosing one of the options below:
In GNOME, select "Menu" > "Applications."
In KDE, select "K menu" > "Google Desktop" > "Google Desktop."
If the above steps do not work, please see
http://desktop.google.com/support/linux/bin/answer.py?answer=66144