“Smartphones” are all the rage these days, with lots of advertisements for the next newest, shiniest phones promising to let you watch movies in full High Definition (HD), take high quality photos and videos, keep in touch with work, and more.

Every other person you see in the office and standing in line at the coffee shop seems pre-occupied and obsessed with these pocket-sized gadgets.

So what is a smartphone, and how do you know which is right for you?

Smartphones allow users to store information, e-mail, install programs, and make calls in one device. The first generation of smart phones appeared a decade ago, and were not much more than a mobile phone combined with features of a handheld computer or PDA (Personal Digital Assistant, think Palm Pilot). Along came the BlackBerry which was the first smartphone designed for wireless e-mail access, and it became popular when many corporations provided them to employees to stay productive while outside the office.

Then came the Apple iPhone, while initially expensive, offered a large touchscreen, a web browser, and many “apps” that people can purchase and download to their phones. The iPhone arguably opened the flood gate to the innovation and competition in the smartphone market today, with other popular choices like Android and Windows Mobile phones.

So if you have had enough of your trusty old mobile phone and want to replace it with a new smartphone, here are some tips.

• Features you use most. If you currently have a QWERTY keyboard on your phone and rely on it for a lot of data entry such as SMS texts or e-mails, you might want to stick with a smartphone with physical keyboard, not just a touchscreen. Don’t overlook features such as GPS and built-in camera/camcorder that would allow you to ditch other devices and lighten the load in your briefcase or purse. And, perhaps the most important feature in Washington state, if you like to drive and talk: hands-free operation.

• The form factor. Since the smartphone is much more than just a phone, there is no argument that a large screen is best, especially for people who use it to write or read a lot. People should think about where they will most likely store their phone when not in use, however, as phones with screen size larger than 4” presents a challenge to fitting into pockets comfortably.

• Operation systems. Just like there is PC and there is Mac, there are about a handful of popular operation systems for smartphones. There are some general characteristics you should note: iPhone has the most apps and perhaps the best looking interface today. BlackBerry is a powerhouse device for email users, especially those needing to maintain multiple mailboxes. Windows Mobile works the most seamlessly with Microsoft Office and corporate Exchange email server. Android (from Google) offer many innovative features and are available on large selection of devices.

• Compare wireless service plans and compatibility. Look at service plans and make sure the carrier’s coverage works where you live, work, and travel. And if you travel internationally, find smartphone that is also a “world phone” that is compatible with the wireless technology used in Europe and other countries.

• Total cost. While upfront cost of getting a smartphone – usually between free and $300 with a 2-year contract – plays a big part in many people’s purchasing decision, it is important to consider the total cost of the wireless plan, including the cancellation fee if you make a change, etc. It may make sense to pay more initially for an unlocked smartphone which could be used on any wireless network, rather than being tied to a specific carrier. The advantage of purchasing an unlocked smartphone is that you can exercise more choice about the type of wireless plan to use, and it is also very easy to switch between carriers if different services are needed, or if you want to travel.

Wen Tseng, CISSP, is a technology and security consultant based in Redmond and former Research Director for Cloud Security Alliance. For questions and information, email wen@tsengconsulting.com.