There are so many things that Google can do, it is no surprise that you may not have known of these gems....
Definitions - Show the definition of any word by typing define followed by the word you want the definition for. For example, typing: define incredible would display the definition of that word.
Local search - Visit Google Local and either setup a default area or enter the area you want to search and the keyword of the place you want to find. For example, typing: restaurant at the above link would display local restaurants.
Phone number lookup - Enter a full phone number with area code to display any publicly available name and address associated with that phone number.
Find weather and movies - Type "weather" or "movies" followed by a post code or city and state to display current weather conditions or movie theaters in your area. For example, typing weather 3175 gives you the current weather conditions for Dandenong and the next four days. Typing movies 3175 would give you a link for showtimes for movies in that area.
Track airline flight - Enter the airline and flight number to display the status of an airline flight and it's arrival time. For example, type:QF400 to display this flight information if available.
Pages linked to you - See what other web pages are linking to your own website or personal blog by typing link: followed by your URL. For example, typing link:http://www.wurth.com displays all pages linking to Wurth.
Find PDF results only - Add filetype: to your search to display results that only match a certain file type. For example, if you are looking for a manual for a Dell XPS computer and want to display PDF results only type: "dell xps" filetype:pdf -- this is a great way to find online manuals.
Calculator - Use the Google Search engine as a calculator by typing a maths problem in the search. For example, typing: 100 + 200 would display results as 300.
Stocks - Quickly get to a stock quote price, chart, and related links by typing the stock symbol in Google. For example, typing: ctx will display the stock information for Caltex Australia Ltd.
Remember to look for the obscure Google headings at www.google.com.au on special milestone days....famous author's and music artist's birthdays, first manned space flight etc. Some days it can be fun to try to guess what event they are celebrating just by looking at the image they have created!