Any self-respecting business man or woman will know how imperative it is to own a smartphone. Not only do you need to keep in touch with clients and colleagues, but you need to make sure you’re not isolating friends and family in the process.

The thing is, you might be tempted to choose a handset for all the wrong reasons. The smartphone that allows you to tweet and Facebook your mates during lunch isn’t necessarily going to impress your boss. You need something for emails, synching schedules and file sharing, but you also need a phone that can handle the demands of your social life. The OS you choose has a huge impact on the phone’s usability, speed and power consumption. As such, it’s worth assessing the merits of the main operating systems before you pocket the flyest-looking number your business expense account will allow.

So what is the best business OS for 2011? Well, Google’s Android, Blackberry’s OS and Apple’s iOS are the big names when it comes to mobile operating systems, but what do they actually offer? Let’s get down to business.

Your first choice would be to use Android 4.0, Google’s latest OS, which is due for imminent release. Also known as ‘Ice Cream Sandwich’, it features improved voice typing that will enable you to bark out orders and multi-task to your heart’s content. Copy and Paste has also had an upgrade, meaning battering out emails will be an effortless task. The new calendar is also more intuitive, with a pinch-and-zoom feature to make specific dates and meetings more accessible. Finally it has face unlock, for when you need to keep documents hush-hush (or want to look cool around others).

Second in the ring is Apple’s iOS5. It’s simple, it’s effective and it’s understandably popular. Siri will look after every one of your meetings, and remind you of that anniversary to boot. Who doesn’t want a personal assistant that doesn’t command a salary? The antenna problem which so plagued previous iPhones has now been fixed as well, meaning you’ll never miss that important call and end up screaming at customer service. All your notifications are shown in one place, and you can wirelessly stream presentations with AirPlay. Sophisticated typography and smooth animation create a beautiful browsing experience.

Last but not least; well, Blackberry needs no introduction. Hailed as producing the pre-eminent business phone, many people see it as being unfriendly, stark and cold. It’s true the company has always been geared towards the business user, but then they’re undeniably good at what they do, so why change? Blackberry was taking care of business back when Android 4.0 was a glint in Google’s eye, with makers RIM offering continuous messaging and a truly functional email system. BlackBerry is top-rated for security, with more end-to-end data encryption than the rest, and for removable storage. Whilst you’ll have fun with an iPhone 4S or Galaxy Nexus, you can’t beat the Blackberry’s physical keyboard for battering out an important email on the go. You won’t find as many decent business apps with Apple or Android either: plenty of apps if you fancy a spot of virtual carp fishing, but that’s not really the goal, is it? Windows Phone 7 also has a good range of professional apps on board and the best way to enjoy them is with a new Nokia Lumia 800 contract.

BlackBerry’s suffered its share of bad press of late, with falling sales and disgruntled customers unhappy at the firm’s well-documented network problems. Provided RIM can convince users that their failings are now firmly in the past, Blackberry should be able to retain its position as the de facto business smartphone. How long it can hold onto its crown remains to be seen. There was once a time when a company called Nokia were the brand of choice for businessmen and women alike. Their once-ubiquitous handsets have not been seen in the City for quite some time.