Does synchronizing google contacts with apple address book send my data to Apple? I am using OS X 10.6.8 and I have a question regarding the address book synchronization.

Does synchronizing google contacts with apple address book send my data to Apple?

In other words, does the address book application directly sync the contacts with google or does this process goes through Apple servers and/or cloud? I am having a doubt because when I started the sync on my MacBook, the MobileMe icon appeared at the right of the menu bar. MobileMe seems to be related to cloud stuff so, is the contact book application directly interacting with google or not?
It does not route through Apple. It syncs directly between Google and your computer. The sync icon you're seeing in the menu bar is probably Sync Services (or iSync), not MobileMe. It's simply a visual indication that it is syncing.

The only case where Apple would potentially see any of this data would be in the event of an application crash, and only if it was in the crash report and only if you allowed it to be sent.