Google is the most popular search engine on the planet. Safari, the default web browser in Mac OS X, has a built in Google search bar in the upper right corner of it's window. This makes it very easy to conduct a search and also means it's very likely that search information can be found if a suspect uses Safari. Knowing what a suspect recently searched for can be helpful to an investigator or help prove intent.
You can use the MacForensicsLab Analyze function to explore the following file: ~/Library/Preferences/com.apple.Safari.plist This is the main plist that needs to be trashed if Safari crashes upon opening or pages refuse to load. This file contains a section titled "RecentSearchStrings". These are the last 10 items that have been searched for in the Google toolbar of Safari. Clearing the browser history in Safari does not clear this information. The same file also shows the most recent files downloaded from Apple and the last search made on the Apple website.