Google’s Search Options Reveal More by Gwen Harris, SLA Courier (Jan 2010)
And since we are sharing secrets, here is my article on making good use of Google's show options to get more from your search results. There are five questions to ask yourself:
1. What kinds of Web content should I be considering?
2. Is there a time dimension? Do I need very recent material or more historical?
3. Am I shopping? Does this question have a product angle?
4. Have I done this search before?
5. Is this a research topic where I will need more information about the page to judge whether it is suitable?