The Apple iPhone will mark its 10th birthday next January — but can anyone imagine the world without it or its principal rival, the Android-based phone launched roughly 20 months later?

Neither of them were the first smartphones — mobile phones combining the convenience of cellphones with the power of computers. But they turned the smartphone from a specialized tool for a small slice of businesspeople into one found in nearly every pocket or purse.

They’re still a business tool, and they’re relied on more and more by all of us, including septic pumpers and drain cleaners. And neither they — nor the data they bring to the palms of our hands — are cheap. But are they worth it, anyway?

You can get smartphone apps to track business mileage, manage cloud-based task lists, and much more. Smartphones can also tie into your databases back at the shop. With features such as Google Maps, they’re supplanting stand-alone GPS devices for many of us. And they allow rapid communication between you and your crews and among crew members themselves — whether by email, text messaging or good old-fashioned voice phone calls (how 20th century!).

‘NAKED’ WITHOUT THEM

Hollis T. Warren Sr. owns Hollis Warren Inc., a septic service located in central Delaware near Dover, the state capital. His drivers have been using Apple iPhones on the job for 10 years — about as long as they’ve been around. “I never thought it would be that big a deal,” says Warren. “But you feel naked if you don’t have one on you anymore.”

They’re a necessary communication tool, he says. Drivers can phone ahead to let customers know they’re on the way. If they lose their way en route to a job, they can call for directions or bring up Google Maps.

The map apps also allow the driver to scope out a customer’s yard configuration before arriving at the job site. Utilizing an app called Planimeter in conjunction with the map, drivers can calculate how long a hose they’ll need to run from the tank to the truck. When the work is finished, the driver can take the customer’s credit card payment on the spot using the phone.

A driver who runs short of a needed part can just call back the office for the item to be driven out to the job instead of having to stop, drive back to fetch it, and then return. By avoiding lost time, “it’s going to save you a lot of money,” says Warren.

Warren’s employees can choose to use their own iPhone or one issued by the business. In either case, they must follow rules: No personal calls or web surfing during work hours. “They’ve got breaks and lunch when, if they’ve got something personal, they can go and use them for that,” Warren points out. And no calls while driving — that’s against Delaware state law unless the driver can talk hands-free.

Before the iPhone, the business used two-way radios. Warren says there’s no comparison between that technology and the iPhones. The radios could only communicate back to the office — and they cost nearly 10 times what an iPhone cost.

“You can spend as much as $5,000 for one radio in the truck.”

He’s never put pencil to paper to measure what the phones are worth, but he estimates they probably net him a 10-15 percent savings on various costs. And that’s even when you consider that his current business data limits are probably too low. “We’re always going over — so it’s expensive using them sometimes,” Warren admits. But the convenience they offer is worth it. “It’s almost like you’ve got a mini office there in your hands,” he continues. “Even with the cost of use it’s still a lot cheaper than the old way of doing things. Time is money, and it saves time.”

THE SMARTPHONE EQUATION

If you don’t have smartphones in your business, chances are you’re wondering about them. But even if you do, you might benefit from a closer look at how you’re using them. Either way, you may want to consider a few important factors about bringing (or keeping) smartphones on the job where you work.

Whose smartphones will your employees use — their own, or a company-issued one?

If they use their own, you’ll need to work out clear and fair policies for reimbursing them for the cost of their phone use for business purposes. You may find an advantage to simply getting everyone a company phone for company business. In either event, be sure to establish clear policies and procedures, as Warren points out. Making sure they can’t fritter away your work time on Words with Friends or Angry Birds games is just the start.

What are the best cellular networks in your region?

Service varies around the country, and as the big carriers continue to invest in improving their coverage, the best carrier this week could fall behind six months down the road. Ask people you know; you could start with your employees, who probably have their own phones already and can tell you about their experiences. Consumer Reports from time to time ranks the various carriers; it wouldn’t hurt to see what the magazine’s most recent report says about the carriers in your area.

What specific plan will be best for your business?

Data plan structures are changing all the time. Early on, carriers offered unlimited data plans (for a definite markup, to be sure); later they backed away from them. Now they’re coming back, pricier than ever — but it’s an open question whether they’re worth the expense. Even “unlimited” plans have their limits: If your usage goes over a certain level, carriers may effectively slow down your data speed.

Under most plans, though, data is priced in increments of 5 or 10GB a month — and if you go over, there’s a premium charge. You can see the dilemm: Do you go with a rich plan that might be more than you need, essentially “wasting” the additional dollars it costs compared to a cheaper plan that’s closer to your actual usage? Or do you go with a lean one, risking that you’ll go over it and have to pony up more?

Only you can decide which answer suits your situation better. Once you do choose, watch your bills: If you’re always paying overage charges, you’ll probably be better off stepping up to a monthly data plan with a higher ceiling. And if you always use a lot less than you’re paying for, you can switch downward after a few months.

Note — I’m saying plans, not carriers; carriers typically lock you into a contract of two years or some other fixed term, which remains in place even if you shift your data plan up or down.

Would you do better on a “pay as you go” plan?

An alternative to going with the big carriers and their two-year contracts is a no-contract plan, paid for by actual usage and able to be terminated at any time. Providers include Tracphone, Ting, Consumer Cellular and others. They may promise substantial savings, but you’ll have to consider your own usage patterns.

Running some hypothetical comparisons with Ting’s calculators, if your actual data usage is way under the big carrier’s monthly data plan limit, you might realize substantial savings by switching. If your usage usually approaches your actual limit, however, the savings don’t appear to show up.

CHOOSE WISELY

Like a lot of business decisions, adding smartphones or switching plans may require you to make some careful comparisons. Take the time and choose the option that best suits your needs. After all, isn’t getting the best deal you can one of the smartest things you can do?