Google has traditionally been pretty good about using logical subdomains (groups.google.com, etc.) instead of feeling the need to register separate Stupid Unnecessary Domain Names [tm] for everything, but perhaps they're getting under the control of the Marketing Types these days.

hey did you know google has about 34 million pages online on the web (and that's just it's own pages). try site:google.com ... (damn)

subdomains are great for SEO