Following is how to disable the Google Update Service.
Knowing that members here use things like Google Earth, Sketchup etc., I thought some might find this information useful, as it is not an easily figured thing.

- -
Having just updated Google Earth, I kept getting request notifications from my firewall that Google Update Service is trying to connect.  All of Google's software includes a 'master' updater to check for new updates AND transmit useage information etc.

The problem is, there is no where to adjust these settings.
If you are like me, and DON'T LIKE software assuming unauthorized access to your computer, then disabling this is the option.
Most software of this type is known as a TROJAN HORSE.  How Google gets away with it is beyond me!

Steps (for XP) to disable the updater and prevent it from returning on reboot:

1: check task-manager and stop the slitherio service if running (Ctrl-Alt-Del / processes)

2: disable the 2 services running the updater:
 A) right click my computer, select 'manage'
 B) click 'Services and Applications', dbl-click 'Services'
 C) Change the startup type for both 'Google Software Updater' and 'Google Update Service'.  This is done by right-clicking the name, selecting 'properties', and changing the startup type to 'disabled'.

3: delete the scheduled task:
 A) Go to Start, All programs, Accessories, System Tools, Scheduled Tasks.
 B) Right-click the GoogleUpdateTaskMachine, select properties, and uncheck the 'Enabled' box

Done!

If this helps even 1 person kill the SUPER ANNOYING and INTUSIVE and TROJAN LIKE Google Updater, than I have done my good deed for the day/week.