1. Search by Site
Ever visited a Web site that had a built-in search function that couldn't find squat? Of course you have. But why bother when Google can search just that site for you? All you need to do is add the "site:_____" command to your Google search.
Google will find every mention of that name at the domain name you picked. What better way to ego surf specific sites? You can even limit yourself to top-level domains (.com, .net, .edu). For example, Google will only search educational institutions if you include "site:edu" in your search string.
Or, you could type the name of a particular online publication first, then the topic you want, and Google can generally find results for you.
2. Find Specific Products
Google Product Search is still in beta, but it might be the fastest way to find a specific item you want to buy. You can also use it to search specific sites, such as Amazon (using the previous "site:" command). The site is meant to replace "Google Shopping" (once called "Froogle"), but you still access it when searching, using Google Web search and selecting the Shopping link at the top of the page.
3. Check the Time and Weather
Want to know the time? Just type "time" and Google Instant will quickly tell you your local time. Type "time in ______" and put in the name of a city and it will tell you the time anywhere on the globe. This is a great way to find out how many time zones away someone is.
The same goes for what's happening outside. Type "weather" in the search box and you'll get a four-day forecast for your local area. "Weather in ______" can reveal the precipitation expectations anywhere there's a forecast. A quick click will transform the temperatures from Fahrenheit to Celsius or vice versa.
4. Calculate and Convert Almost Anything
Not sure where your old Texas Instruments calculator is? Get the calculation you need by using Google's search box. You don't need to enter any special command, just type something as simple as "2 x 2" (Google will tell you the answer) or you can enter something more complicated and Google will calculate it for you.
Google can tell the difference between 5*5-3 (22) and 5*(5-3) (10). And yes, it can use both an "x" or an "*" to multiply. That's just the start, since the calculator can handle advanced math, such as trigonometric functions.
Google also makes converting measurements a breeze. Ask Google "3 meters in yards" and you'll be told "3 meters = 3.2808399 yards." You can convert volume, distance, area, currency, energy, information (bits and bytes), and, well, just about anything you can measure.
You can also combine conversions with calculations. For example: (3 meters) + (2 feet) = 0.00224290146 miles
(1 hectare) + (2 acres) = 18093.7128 m2
GoogleGuide has a great calculator/converter shortcut table, too, that you'll find invaluable.
5. Learn Your Operators
Commands like "Site:" are handy, but nothing beats knowing which operators to put in front of words to narrow or expand your searches.
For example: Tilde (~) - if placed in front of a word, results will include related words
Plus sign (+) - ensures your searches include that word
Minus sign (-) - that word will not be on any page in your search results
Asterisk (*) - if you're not sure how to end a phrase, use the asterisk as a wild card and Google will fill in the blanks
OR - use this Boolean operator to find results with both terms entered
6. Track Packages
Expecting a delivery from UPS, FedEx, or the U.S. Postal Service? Enter the package's tracking number into the Google search box and it will auto-magically find where your box is and give you a quick link to the shipping company's data.
7. Track Earthquakes
The U.S. Geological Survey tracks all seismic movement the world over. In the wake of the devastation in Haiti and Japan, maybe it's not a bad idea to know what's going on near you, tectonically speaking. Type "earthquakes" into Google and you'll instantly get a list of the most recent quakes in the world, what magnitude they hit on the Richter scale, and links to maps of the epicenters.
8. Pick a Type
If you know you only want to find a certain type of file, then you can ask Google to only look for that file type by using the "filetype:" operator with the file extensions typically used in Windows. This includes Acrobat (PDF), Word (DOC), text (RTF and TXT), Excel (XLS), and PowerPoint presentations (PPT), to name just a few. If you don't specify, Google will include all these file types in the search, but don't expect them to be at the top of most results. If you want to search multiple file types, separate them in the search with the "OR" operator ("free software filetype:PDF OR filetype:DOC").
If you're doing a Google Image search, you can narrow the search by checking the area to the left where you can specify a search for clip part, photographs, or line drawings.
9. Go Beyond the Dictionary
The "define:" search operator does so much more than just go to a dictionary. Sure, you can get the definition of any word you can imagine, but it will search more than just individual words, checking acronyms, phrases, tech terms, and even slang. Results could come from Wikipedia, Wiktionary, WordNet, or just about anywhere that has definitions and encyclopedic knowledge.
10. Google It for Someone
Got someone in your life who acts like they can never find anything online, even though the power of Google's search is practically screaming in their face? Feel free to exacerbate the problem by using Let Me Google That For You (a site not affliated with Google). You type in a query and LMGTFY spits out a tiny URL that you can send to the person. When they click it, they get an animation of just how easy it would have been to type it themselves. The added "Was that so hard?" helps twist the knife. Of course, this works with any of the search queries above, so you can use it to answer questions about calculations, conversions, weather, packages, and more-obnoxiously.