Owning a smartphone is like your first taste of sushi - it takes a while to try, but afterwards, you wonder how you lived without it. Is it a coincidence that, while I sat at a café writing this article, four out of five people had an iPhone, and the fifth a Blackberry?

For personal productivity and business prowess, they're a 2010 necessity. Here are my reasons why.

Make more sales

Applications that your customers or prospects can download should be created for branding, or to increase sales.

Three months ago Pizza Hut launched an iPhone application (available through iTunes, but only in the US) for ordering pizza, pasta and wings. Not only has it brought in an extra US$1 million ($1.3 million) in sales during this period, it has also created a huge buzz simply by incorporating the "cool" things you can do with the iPhone. Stretch or shrink the pizza base with your fingers to select a small, medium or large. Scroll for toppings and drag them on, and tap and tilt to have the topping on half the pizza. Select sauce for wings and watch it pour on. Shake the phone to spread the sauce through the wings. They have even included a Pizza Hut racing game to play while waiting for the pizzas to be delivered.

Get information as fast as you need it

Got an appointment at an address you're not sure of? Google the company on your smartphone, and click on the address to see where it is on the built- in map. You can even use Streetview to see what the building looks like - so you know where it is, how to get there and even what building to look for.

Another fabulous example of iPhone and Google Android technology is augmented reality (the addition of virtual reality to reality).

In New Zealand, Wikitude (a free iPhone application) uses the GPS location, compass and video camera, so as you look through your phone's camera, logos and information can be laid over what you are looking at. For example, you can check reviews and get additional information for a restaurant you're standing in front of, just by pointing your phone at it.

Get more done

Talking about this article at the dinner table, I asked my husband (who is a chief information officer) what his thoughts were. He put it quite succinctly: "With a smartphone, you have 75 per cent of the functionality of your desktop computer, yet total freedom from your desk."

Think of the freedom it gives you to leave the office to network, schmooze and develop more clients. Instead of coming back to piled up communications, you'll be able to stay on top of them while out of the office. The application, Documents to Go (US$5), gives you access to your entire Microsoft Office suite from your phone. You can use it to edit, create and view Word documents, as well as view and synchronise Excel, PowerPoint, PDF and other files.