In the old days, it was far easier to get "strongarmed" by your wireless carrier. Today, it is very easy to "get an immediate "separation" from your carrier, if they no longer meet your expectations. As long as your SmartPhone is paid off, by law, your carrier must unlock it, if requested. Apple's newest iPhone 6s series supports 23 different LTE frequencies. With both T-Mobile and Sprint still buying out contracts from the other carriers, it's easy to take your number, even with your current device in most cases, to another carrier.
2) Verizon does not Unlock their iPhone devices as all the other carriers.
I have no explanation why, but since Verizon abandoned the CDMA platform for LTE, all of their iPhones are shipping already unlocked. Every iPhone from the iPhone 5 model is unlocked and can be used out of the box with T-Mobile, AT&T or any other carrier. When buying a device from the other carriers, they are always locked to that carrier and cannot be unlocked without the carrier's approval. It is also possible to buy unlocked devices directly from Apple or Dr WIreless.
3) Wifi voIP dialing is now available with all four carriers.
T-Mobile has offered this for 6 years. Sprint started about 6 months ago. AT&T and Verizon did not want to offer this until getting an official waiver from the FCC which both just did. Wifi dialing has many advantages. Anywhere that you can get a wifi signal, you can make wireless calls, regardless of cellular coverage. The calls go out with your internet provider. The best kept secret of wifi dialing is it totally circumvents roaming charges. Anytime you are out of the country and use wifi dialing to call the country you are in, or back to your home country, it is totally FREE. I'm guessing that was why AT&T and Verizon were in no hurry to implement this. For iPhone users, go to settings>phone and see if there is an option for wifi dialing. If so, turn it on and enjoy.
4) Tired of boring cellular voice mail? There are better FREE options.
There are actually many great 3rd party voice mail solutions that are far better than your generic carrier voicemail. Several are actually FREE. The two that I prefer are Google Voice Mail and YouMail.
Google Voice mail actually integrates with your mobile number and does many amazing things. My favorite is free speech to text messages. I can read voice mail while in meetings, or listen to an audio file in case the transcription is less than perfect. With YouMail, they offer a very personalized free service that impressively greets your callers by name, providing they are in your contact list.
5) Have you ever traveled and forgot to bring your charger?
This might sound too easy but it has worked for me several times and I have had clients tell me it worked for them. Next time this happens to you, go to the hotel concierge and tell them you believe you left your SmartPhone charger during your last visit. They will break out a giant lost and found box with plenty of chargers. Today, the two most common styles are the Apple Lightning connectors and the MicroUSB size used by most Android makers. They will likely also have the older, mini USB style and older Apple connector for the 3 and 4 series. As a good karma courtesy, please leave the charger in your room so it ends back up in the lost and found box for the next person who needs it.