There are rumors at the forums that when you see a referral from "gnome.corp.google.com" it means that a Google AdSense representative is conducting a manual review of your Web site. The most recent thread that discussed this was at SEO Chat Forums. The SEO Chat thread references back to a WebmasterWorld thread named Google Monitoring.... That thread, dated back on Jan 8, 2004, Jenstar (AdSense Guru) said "GoogleGuy had commented on this before, and said their employees, just like employees at other companies, will surf from work." That is not the only WebmasterWorld thread on this topic, there is also a thread that started on Feb 22, 2005 that discusses this "strange referral."