(MoneyWatch) Depending upon your perspective, Siri is either an essential voice-controlled boon to iPhone users or a worthless gimmick that loses its appeal about 10 minutes after buying that smartphone. The reality, I think, is somewhere in between. There are a half-dozen situations I face almost every day in which it's easier to ask my phone to do something than to do it myself manually. And when those arise, I am very thankful for Siri.  If you're not familiar with Siri, it's easy to get started: Press and hold the Home button on your phone. After a moment, Siri will beep and you'll see the text, "What can I help you with?" Ask your question and wait for the response. You can also configure Siri to launch when you hold the phone to your head (Options, General, Siri, Raise to Speak), but be warned: Doing so will run down your battery much more quickly.  Ready for some unexpected or less common things you can ask Siri to do? Here are some of my favorites:  Start a timer. I do this all the time in the kitchen -- just say something like, "Give me a five-minute timer," and Siri will set the timer for you right away.  Make a conversion. Siri is also a great kitchen aid and allows you to make conversions between different units and even between nonmetric and metric systems. You can ask, "How many cups are in two liters," or "How many teaspoons in three tablespoons?" Siri will do the calculations for you.  Calculate a tip. Continuing the food theme, Siri can rapidly calculate a tip for you: Just ask, for example, "What's 15 percent of 110?"  Make a reservation. Before you get to the tip, though, you have to dine in a restaurant. If you have also installed OpenTable, Siri can make a reservation for you at the bistro of your choice. Try: "Make a reservation for The Melting Pot for next Tuesday at 8."  Perform math word problems. Siri is plugged into Wolfram Alpha, which means that you can ask your iPhone how to do some unexpectedly complicated things. For example, ask, "How long does it take to go 300 miles at 70 miles an hour?" The answer comes quickly: 4.3 hours. You can also ask how long it takes to drive to a specific place -- say, "How long does it take to go from here to Seattle" -- and Siri will create a route for you in Maps.  © 2013 CBS Interactive Inc.. All Rights Reserved.
The iPhone's voice recognition tool is surprisingly versatile and convenient -- it can even do the math and calculate a tip