Forget the consumer advertisements. With secure access to corporate networks, thousands of third-party business applications and an enterprise developer program for in-house applications, Apple’s iPhone 3GS is ready to go to work. I was reluctant to switch from my Windows Mobile handset three months ago, but I have never looked back. I’m not here to sell iPhones—I bought one a few months back and I’d like to share my experiences with those thinking of buying a new phone for business use. For my full review of the iPhone 3GS, go here.

Although the iPhone still isn’t used at the same sort of level as BlackBerry, Symbian and Windows Mobile-based handsets in business, the iPhone is a fantastic personal device for individuals that effortlessly extends to business. By day you can manage your calls, calendar, contacts, e-mails and even blogs, and by night—or even while commuting—you can catch up with the latest news, sports results, and relax to Internet music streaming services such as Last.fm and Spotify (at last!). Then there are games, photos, videos, location-based services, and a raft of other time-consuming stuff to get lost in.

Apple’s iPhone has only been around since 2007, but in those two years it has out-sold every other touchscreen device in the UK and U.S. The uptake in businesses is high too—thanks largely to security enhancements in the software and hardware—and IT departments are now supporting them just as they support BlackBerrys and Windows Mobile phones. But what is it that makes the iPhone a suitable tool for business users?

The most significant selling point of the iPhone—at least for me—is its operating system. Fine-tuned by Apple, the touchscreen interface is a design masterpiece that leaves Windows Mobile and a Blackberry handsets for dust. The best thing about Apple products is that you don’t need to be a tech-head to appreciate them. With the iPhone everything is done within a couple of taps—from managing missed calls, to listening to voicemail, to responding to text messages. Quite rightly it puts the user experience first and the hardware second.

I tend to scoot between offices—mainly to avoid rent—so staying in touch is critical. With the iPhone I’ve never found it easier to access my e-mail, view attachments, and sync with Outlook. Support for Windows Live Mail is painfully missing, but Gmail support is built in so you can piece together a workaround. All the usual business mail protocols are supported—including Exchange—and the huge display makes reading a snap. The native e-mail application is really easy to use and Gmail works beautifully with it. Furthermore, the iPhone has the best Web browser by far, making life so much easier in my field of Web-based work.

For me, the iPhone’s interface and the way the applications look and feel separate it from the crowd. It is consistently a pleasure to use—in contrast to virtually every mobile device I’ve owned previously—and it rarely crashes. Supporting the iPhone with Exchange servers is easy enough, although occasionally an Exchange account becomes unresponsive on the iPhone. Sure there are more powerful phones out there with faster processors, bigger screens, and a better battery life. But that’s not the point. The iPhone lets you get the job done like no other phone.

One aspect that makes the iPhone such a successful business tool is the range of applications available from the App Store. To date there are around 75,000 available, both free and paid for, covering pretty much everything you could ask for. Big names are on there too, including Oracle, Sybase, SAP, Salesforce.com, Netsuite, SugarCRM and Zoho. Other useful applications let you convert currencies, as well as find the nearest hotels, restaurants and dry cleaners. Google Maps and GPS have helped me walk around unfamiliar streets a couple of times, and social networking tools let me communicate with my clients’ customers.

Strangely, Apple reminds customers that applications sold through the iTunes store are strictly for non-commercial use: “The iTunes Store sells only to customers as end-users for personal, noncommercial use.” The issue arises thanks to Value Added Tax—a sales tax applied in slightly different ways across Europe. In the UK, VAT is payable on luxury items and is reclaimable by businesses—businesses don’t have luxuries. But Apple won’t provide a receipt in order to reclaim VAT on the grounds that iPhone applications aren’t for commercial use and therefore can’t be used by a business that would be allowed to reclaim the VAT. Which begs the question: is everyone ignoring Apple’s T&Cs? Or is it just me?

It’s difficult to conclude. Ultimately, the iPhone makes it easier to communicate and be more responsive. There are lots of things I do on it that remove the need to boot my clunky laptop. Be it for personal or business use, I’ve never been so contactable and available through text, mail, VoIP or the traditional method of the phone call. Sure there’s the issue of high cost of ownership, but I believe the iPhone has been an invaluable business tool and helped me to grow my business. And it’s even more attractive now that it is available from multiple mobile providers.