• WHAT: Key combinations on your cell phone that trigger features you may not know about
• WHY: You might need the services/information these reveal sometime
• COST: Zero - totally free

Ah, the tiny 12-key keypad on the cell phone... the mysteries they reveal.  The services they trigger.  Just like many other things in life, if you know what buttons to press there's no telling what results you can generate.  It's not just pressing and holding the "1" key to get voicemail that your fingers can activate - there's more. 

Here are a few of the cool functions that I know of offhand that you might find helpful in using your cell phone more effectively:

"0" - Press and hold this key and, voila, a "+" sign appears.  Big deal, you say?  It is when you're trying to make an international call.  And if you spend any time in Europe, let me tell you, it sure seems like every call is international.  Before you can call an international number you need to enter the "+" sign and the country code.  So, for example, even if you're in the UK, if you have your own cell phone with you you'll have to enter "+41...." followed by the city code and phone number.  

"*#06#" - Enter this combination of numbers and symbols on virtually any phone and a 15-digit number appears on your screen.  Surprise - it's your phone's serial number.  If your phone is ever lost or stolen, or you need to reference the serial number when you send it in for service, it's right there.  (If you've ever tried to read the 3-point, itsy-bitsy-type on the label under the battery on the back of they phone you'll thank me for this one.)

"112" - It's the "911" of the international set.  Call "112" anywhere in the world and it will connect you with the local authorities.  Here in California entering this combination on your cell phone puts you in touch with the "CHiPs" (California Highway Patrol).  Where does it connect to in your neighborhood?  Tell me by clicking HERE and I'll add it to this post. 

"611" - Need to get in touch with the customer service department for your cellular carrier?  Stop fumbling around looking for their toll-free number... just call "611" (some carriers might still be using the older "*611") and you'll get connected right away.  I'm not sure if you actually get popped to the top of the queue by calling from your cell phone, but if I was running the system I'd sure set it up that way so that customer service calls from actual customers were handled first and, no small thing, you'd get them off the network sooner, thus freeing up the ever-valuable resource of free channels.  

"#" - On some phones this key, when pressed and held, has a special function.  You'll have to try yours to find out.  For example, on my RAZR V3xx, pressing that key switches the ringing mode from any ring tone or audible ring to a vibrate-only mode... a great shortcut to get you in stealth mode for movies, meetings, etc.  Press-and-hold it again and it restores your ring setup to its regular state.  Very handy.   

"411" - Here's one you do NOT want to use.  The cellular carriers will charge you about $2 for this service and you can get the same information free by calling 800-FREE-411.  See my earlier post about that HERE. 

Any exterior button - I haven't been able to try this on every model and every manufacturer, but on the cell phones I have been able to test it on, the outside screen (which almost always shows the time, updated by the cellular carrier every time you turn on the phone or at least daily) lights up.  If you need a quick look at the time this is an easy way to do it.

Do you have any other cool key combinations that make your phone do tricks?  If they work universally (meaning across most phones, not just on yours) and I blog about it, I'll send you a $5 Starbucks card.  Just click HERE to fill out the form and when I publish your tip I'll send out the card.  Now that's a shortcut to free coffee you shouldn't do without!