Google calling home from my system, what is the package?

[stan]

Hi,

I've been noticing that my modem lights would flash as if receiving or
sending data when the system was idle for IO.  I could never find what
was doing this.

Today I happened to have iftop running and noticed the modem lights
flashing.  I was able to find the domain name of the other end of the
interaction - nuq04s01-in-f132.e100.net.  I did a ping and then a whois
lookup on the IP address 74.125.19.132 and it turns out this is
google.  

I don't want such calling home occurring on my system. How can I find
out what is doing this and eliminate it or stop it from calling home?