Google Hacks

Web Search Basics
preface:
Searching in Google doesn't have to be a case of just entering what you're looking for in the search box and hoping for the best. Google offers you many ways—via special syntax and search options—to refine your search criteria and help Google better understand what you're looking for. We'll dig into Google's powerful, all-but-undocumented special syntax and search options, and show how to use them to their fullest. We'll cover the basics of Google searching, wildcards, word limits, syntax for special cases, mixing syntax elements, advanced search techniques, and using specialized vocabularies, including slang and jargon.
Google Web Search:
Phrase Searches
On entering a search for keywords:

to be or not to be

Google will find matches where the keywords appear anywhere on the page. If you want Google to find you matches where the keywords appear together as a phrase, surround them with quotes, like this:"to be or not to be"Google will return matches only where those words appear together.
Basic Boolean
Google's Boolean default is AND, which means that, if you enter query words without modifiers, Google will search for all of your query words. For example, if you search for:snowblower Honda "Green Bay"
Google will search for all the words. If you prefer to specify that any one word or phrase is acceptable, put an OR between each:snowblower OR snowmobile OR "Green Bay"NOTICE:[Make sure you capitalize the OR; a lowercase or won't work correctly.]
If you particularly want one term along with one of two or more other terms, group them with parentheses, like so:snowblower (snowmobile OR "Green Bay")
This query searches for the word "snowmobile" or phrase "Green Bay" along with the word "snowblower." A stand-in for OR, borrowed from the computer programming realm, is the (pipe) character, as in:snowblower (snowmobile "Green Bay")
Negation
If you want to specify that a query item must not appear in your results, prepend a - (minus sign or dash):snowblower snowmobile -"Green Bay"
This will search for pages that contain both the words "snowblower" and "snowmobile," but not the phrase "Green Bay."
Note that the - symbol must appear directly before the word or phrase that you don't want. If there's space between, as in the following query, it won't work as expected:snowblower snowmobile - "Green Bay"
Do be sure, however, that there's a space before the - symbol.

Explicit Inclusion
On the whole, Google will search for all the keywords and phrases that you specify (with the exception of those you've specifically negated with -, of course). However, there are certain words that Google will ignore because they are considered too common to be of any use in the search. These words—"I," "a," "the," and "of," to name a few—are called stop words.
You can force Google to take a stop word into account by prepending a + (plus) character, as in:+the king
Stop words that appear inside of phrase searches are not ignored. Searching for:"the move" glam
will result in a more accurate list of matches than:the move glam
simply because Google takes the word "the" into account in the first example but ignores it in the second.

Synonyms
Every so often you get the feeling that you're missing out on some useful results because the keyword or keywords you've chosen aren't the only way to express what you're looking for.
The Google synonym operator, the ~ (tilde) character, prepended to any number of keywords in your query, asks Google to include not only exact matches, but also what it thinks are synonyms for each of the keywords. Searching for:~ape
turns up results for monkey, gorilla, chimpanzee, and others (both singular and plural forms) of the ape or related family as if you'd searched for:monkey gorilla chimpanzee
and some you'd never have thought to include in your query.

Number Range
One of the more difficult things to convey in an Internet search query is a range—of dates, currency, size, weight, height, or any two arbitrary values.
The number range operator, .. (two periods), looks for results falling inside your specified numeric range.
Looking for that perfect pair of Prada pumps, size 5 or 6? Try this for size:prada pumps size 5..6
Perhaps you're looking to spend $800 to $1,000 on a nice digital SLR camera; Google for:slr digital camera 3..5 megapixel $800..1000
The one thing to remember is always to provide some clue as to the meaning of the range, e.g., $, size, megapixel, kg, and so forth.
You can also use the number range syntax with just one number, making it the minimum or maximum of your query. Do you want to find some land in Montana that's at least 500 acres? No problem:acres Montana land 500..
On the other hand, you may want to make sure that raincoat you buy for your terrier doesn't cost more than $30. That's possible too:raincoat dog ..$30
Simple Searching and Feeling Lucky
The I'm Feeling Lucky© button is a thing of beauty. Rather than giving you a list of search results from which to choose, you're whisked away to what Google believes is the most relevant page given your search (i.e., the first result in the list).

Case Sensitivity
Some search engines are case sensitive; that is, they search for queries based on how the queries are capitalized. A search for "GEORGE WASHINGTON" on such a search engine would not find "George Washington" "george washington" or any other case combination.
Google is case insensitive. If you search for Three, three, ThrEE, even ThrEE, you get the same results.
Special Syntax
Full-Word Wildcards
Google does offer a full-word wildcard. While you can't have a wildcard stand in for part of a word, you can insert a wildcard (Google's wildcard character is *) into a phrase and have the wildcard act as a substitute for one full word. Searching for "three * mice", therefore, finds three blind mice, three blue mice, three green mice, etc. One * is a stand-in for one word; two * signifies two words, and so on.

The 10-Word Limit
Google has a hard limit of 10 words—that's keywords and special syntaxes combined—ignoring anything beyond.

Special Syntax
intitle:
intitle: restricts your search to the titles of web pages. The variation allintitle: finds pages wherein all the words specified appear in the title of the web page. eg:
intitle:"george bush"
allintitle:"money supply" economics

intext:
intext: searches only body text (i.e., ignores link text, URLs, and titles). While its uses are limited, it's perfect for finding query words that might be too common in URLs or link titles.
intext:"yahoo.com"
intext:html
There's an allintext: variation, but again, this doesn't play well with others.

inanchor:
inanchor: searches for text in a page's link anchors. A link anchor is the descriptive text of a link. For example, the link anchor in the HTML code O'Reilly Media is "O'Reilly Media."
inanchor:"tom peters"
As with other in*: syntax elements, there's an allinanchor: variation, which works in a similar way (i.e., all the keywords specified must appear in a page's link anchors).

site:
site: allows you to narrow your search by either a site or a top-level domain.
site:loc.govsite:edu.cn
Be aware that site: is no good for trying to search for a page that exists beneath the main or default site (i.e., in a subdirectory such as /~sam/album/). For example, if you're looking for something below the main GeoCities site, you can't use site: to find all the pages in http://www.geocities.com/Heartland/Meadows/6485/; Google returns no results. Use inurl: instead.

inurl:
inurl: restricts your search to the URLs of web pages.An allinurl: variation finds all the words listed in a URL but doesn't mix well with some other special syntax.
inurl:help
allinurl:search help
You'll see that using the inurl: query instead of the site: query has one immediate advantage: you can use it to search subdirectories.
You can also use inurl: in combination with the site: syntax to draw out information on subdomains. For example, how many subdomains does oreilly.com really have? A quick query will help you figure that out:
site:oreilly.com -inurl:www.oreilly.com
This query asks Google to list all pages from the oreilly.com domain, but leave out those pages which are from the common subdomain www, since you already know about that one.
link:link: returns a list of pages linking to the specified URL. Enter link:www.google.com and you'll get a list of pages that link to the Google home page, http://www.google.com/ (not anywhere in the google.com domain).

cache:
cache: finds a copy of the page that Google indexed even if that page is no longer available at its original URL or has since changed its content completely.
cache:www.yahoo.com
If Google returns a result that appears to have little to do with your query, you're almost sure to find what you're looking for in the latest cached version of the page at Google.
The Google cache is particularly useful for retrieving a previous version of a page that changes often.

daterange:daterange: limits your search to a particular date or range of dates on which a page was indexed. It's important to note that a daterange: search has nothing to do with when a page was created, but when it was indexed by Google.
filetype:
filetype: searches the suffixes or filename extensions.You can even search for different page generators—such as ASP, PHP, CGI, and so forth—presuming the site isn't hiding them behind redirection and proxying. Google indexes several different Microsoft formats, including PowerPoint (.ppt), Excel (.xls), and Word (.doc).
homeschooling filetype:pdf
"leading economic indicators" filetype:ppt

related:
related:, as you might expect, finds pages that are related to the specified page. This is a good way to find categories of pages; a search for related:google.com returns a variety of search engines, including Lycos, Yahoo!, and Northern Light.
related:www.yahoo.com
related:www.cnn.com

info:
provides a page of links to more information about a specified URL. This information includes a link to the URL's cache, a list of pages that link to the URL, pages that are related to the URL, and pages that contain the URL.
info:www.oreilly.com
info:www.nytimes.com/technology

phonebook:, as you might expect, looks up phone numbers.
phonebook:John Doe CA
phonebook:(510) 555-1212