Google.com Integration is a feature of Google Desktop that inserts a line of Desktop results above your Google Web Search results. Although your personal and web search results are shown together on your computer, your personal information is not sent to Google.
If you don't want to see Google Desktop results on your web search results pages, you can turn this feature off. Just go to the Apple menu > "System Preferences." Click "Google Desktop," then click "Search Results" and deselect the "Enable Google.com integration" box.