From today's San Francisco Chronicle:
"Strange de Jim shares a revelation from Janet Lowe's book, "Google Speaks: Secrets of the World's Greatest Billionaire Entrepreneurs": NASA wanted to use the Google Boeing 767 jet last summer to observe and record re-entry data from the Jules Verne ATV-1 space freighter, but the plane was otherwise occupied. Google was using it to ferry guests to Montana for Gavin Newsom's wedding to Jennifer Siebel. NASA made do with an old DC-8."
So that's why we're putting up with a jet at Moffett Field, so that millionaires can ferry other millionaires to expensive parties.