Google tricks/Google tips, does not mean hacking google, Using the below Google operators, we can get the desired Google result very quickly. Well we can name this as hidden Google secrets or Advanced Google searching.
GOOGLE OPERATOR  
Type the following highlighted words in Google search box.
Google has several google operators        that can help you find specific information, specific websites or inquire        about the indexing of your own   site, below you will find the most        important ones:         define:        - This google operator will find definitions for a certain term or  word over the        Internet. Very useful when you come across a strange word when writing a        post. I use this as a google dictionary. example : (define        computer)
info:        - The google info operator will list the sets of information that    Google has from        a specific website (i.e.       info:www.yahoo.com)
site:        - This google operator can be used to see the number of indexed     pages on your        site (i.e.site:www.yahoo.com).                  Alternative it can also be used        to search for information inside a specific        site or class of sites.        
       link:        - This google link operator allows you to find backlinks pointing         to your site.        Unfortunately the count is not updated frequently and             not all backlinks        are shown
       allinurl:        - Using this Google operator will limit the search to results         that contain the        desired keywords on the URL structure. (i.e. allinurl:hackingtips)
              file formats:Sometimes you know that the information you are looking for is likely to be contained in a PDF document or on a PowerPoint presentation, for instance. (i.e. “fileformat:.pdf market research” will search for PDF documents that contain the terms “market” and “research”)
-            Google trick to search different file formats (keyword filetype:doc)
-            Google trick to search educational resources (keyword site:.edu) example (computer site:.edu)
-            Finding the time of any location (time romania)
-            Finding the weather of any location (boston weather)
-            Tracking commentary of live events (Olympic games Beijing 2008)
-            Using Google as a calculator (9 * 10)(143+234)(119-8)
-            Converting currencies (1 USD in INR)(10 US Dollars in Indian Rupee)
-            Find how many teaspoons are in a quarter cup (quarter cup in teaspoons)
-            how many seconds there are in a year (seconds in a year)
-            Tracking stocks (stocks:MSFT)
-            Finding faces (add imgtype=face to the URL)
       Top Essential Google Search shortcuts
#1: Get Local Weather
Type:        “weather [city name or zip/postal code]”                    Example: “weather 500054″ or “weather boston”
#2: Check Flight Status
Google automagically pulls        flight data from FlightStats.com. All you have to do is enter the flight        number.                                     Type: [flight name and/or number]                             Example: “bc254″ or “newyork21″
#3: Convert Distances
Type: “[value] [first distance unit] to [second distance unit]” Example: “100 kilometers to miles”
#4: Find a Phone Number
Find a Person:
           Type: “[person’s name], [city or zip/postal        code]”                     Example: “john smith, london”
Find a Business/store:
           Type: “[business name or type], [city or        zip/postal code]”                     Example: “book store, boston”
       Google search trick for Rapidshare files search: 
#1 site:rapidshare.com        inurl:users "*"
#2 site:rapidshare.de inurl:users "*"
#3 site:rapidshare.com inurl:files "*"
#4 site:rapidshare.de inurl:files "*"
#5 site:rapidshare.com inurl:users (pass|password)
#6 site:rapidshare.de inurl:users (pass|password)
Suppose u need some info on ebooks. Then u can try following keyword to see all rapidshare folders having any hacking related thing in it
site:rapidshare.com inurl:users "ebooks"
#2 site:rapidshare.de inurl:users "*"
#3 site:rapidshare.com inurl:files "*"
#4 site:rapidshare.de inurl:files "*"
#5 site:rapidshare.com inurl:users (pass|password)
#6 site:rapidshare.de inurl:users (pass|password)
Suppose u need some info on ebooks. Then u can try following keyword to see all rapidshare folders having any hacking related thing in it
site:rapidshare.com inurl:users "ebooks"