NEW YORK ( TheStreet) -- iPhones come and go, but the old ones don't need to go very far to still be useful -- or to net owners a few hundred extra dollars.

With the latest versions arriving Sept. 20, Apple ( AAPL - Get Report) aims to expand its iPhone user base while keeping its existing one. The lower-priced iPhone 5C should appeal to tighter budgets, while the more-advanced iPhone 5S will lure existing users to upgrade because of features like the 64-bit chip, fingerprint reader and better camera. Or they just might want to have a gold iPhone.

If you're upgrading, you might as well milk your older-generation iPhone for all it's worth. And for some iPhone owners, you can get paid to upgrade. Or you can save money by turning an old iPhone into a household appliance.

Sure, you can give your old iPhone to your kid, as many do, or recycle it at the local electronics recycling canister. But new iPhones don't come cheap -- even the "budget"16 GB iPhone 5C is $99 plus contract -- so make your old one pay for itself.

1. Trade it to Apple for credit on a new iPhone.

Apple knows that iPhones are ubiquitous and that nearly anyone who wants one has one. So, to tempt existing users to upgrade, Apple now exchanges old iPhones for credit toward new ones -- some news outlets report as much as a $279 credit on a new iPhone with contract.

Apple won't offer specifics, but did respond with this statement:

"iPhones hold great value. So, Apple Retail Stores are launching a new program to assist customers who wish to bring in their previous-generation iPhone for reuse or recycling. In addition to helping support the environment, customers will be able to receive a credit for their returned phone that they can use toward the purchase of a new iPhone." To get an idea how much your old iPhone is worth, you must visit an Apple store.

2. Sell it for cash or store credit.

Electronic recycling programs aren't in business (for the most part) out of the goodness of their hearts. It's all about money -- for them and the iPhone user. Over at Amazon ( AMZN - Get Report), a 16 GB white iPhone 5 in great shape can net you a $300 gift card. Amazon, in turn, has a company reselling a similar refurbished iPhone for $530. Of course, you likely purchased the phone less than a year ago for $649, or around $199 with a contract.

But if it's not in such swell shape, sites like Gazelle will even pay for your broken iPhone -- up to $125 if it doesn't even power on!

And if the price of the latest iPhones appeals to you, well, you can get rid of an iPhone 5 while it's still at its peak: NextWorth, which handles trade-in programs at Target, offers up to $340 in Target store gift cards. estimates an iPhone 5 can pull in up to $444. The catch? Someone must be willing to pay for it.

3. Permanent home-music system.

There are all sorts of speakers to help blast an iPhone's music collection around the house. But who wants to leave their iPhone in one part of the house?

Of course if you have no other use for an old iPhone, even the early generations offered a decent music set up, thanks to streaming your entire iTunes library or using multiple apps to explore new music.

Pair an old iPhone with a speaker like the Gramophone from Restoration Hardware and your old phone becomes enormously useful and a dinner conversation.

4. An extra TV remote.

Everyone can use an extra remote control for the TV. And with an old iPhone, there are several apps to turn the phone into a universal remote, allowing it to control many different devices while you're sitting on the couch. Most apps require a hardware translator, like the Dijit app paired with the Beacon from Griffin Technology or the Logitech ( LOGI - Get Report) Harmony Ultimate Hub, which pairs with a Harmony Control App. Also, check with the TV's maker or your TV service for an app to control devices. Samsung ( SSNLF), LG and Time Warner Cable ( TWC) all offer apps.

5. Emergency phone.

Wireless carriers are required to complete 911 calls, regardless of whether the phone is activated or has a SIM card. So, toss your old iPhone into an emergency kit or your car for that unlikely emergency. Keep in mind, the phone needs to stay charged and should you need to dial 911, tell the operator exactly where you are; a wireless phone's location is just to the nearest tower and not reliably accurate. If you get disconnected, call back since the phone no longer has an assigned number.

6. Baby monitor.

New parents tend to splurge on pricy baby monitors. Whether it gets used is, well, not part of marketing baby products. Instead, try a $3.99 app that turns an iPhone (or iPad) into a two-way video station. Baby Monitor 3G syncs two iOS devices, turning one into the baby station, the other into the parent station. Leave one in the baby's room and it will stream live video over Wi-Fi to the parent's phone, or alert parents when the baby moves. You can also use it to speak to the baby while in another room.

Of course, an iPhone or iPad is even more expensive than a $100 baby monitor system, but if you've got an iPhone to spare, this is a good test to see whether the family would benefit from a baby monitor. Or at least you'll get a hassle-free monitor for travel.

7. GPS for the car.

Smartphones with GPS systems come in especially handy when you don't have a dedicated GPS for the car. With an old iPhone, now you do. Keep its Wi-Fi on and it'll update when you pull into the garage.

This article is commentary by an independent contributor, separate from TheStreet's regular news coverage.

Email Tamara Chuang at and follow her on Twitter @gadgetress.

Tamara Chuang is an outside contributor to TheStreet. Her opinions are her own.