Factors that are important when choosing a smartphone include, but are not limited to operating system, keyboard, memory, camera, email access, screen, and phone plan. We'll look at each of these in turn.

Operating system
The most popular operating systems used in smartphones are Windows Mobile OS, Symbian OS, Palm OS, and Blackberry -- and to some extent, a variation of Apple's OS X. The Symbian is the most popular operating system used in smartphones worldwide and is used by most handset manufacturers including Motorola, LG and Samsung.

To some extent the type of operating system chosen will be dependent on your most used applications. For example, if you will be using mostly Microsoft application,s a smartphone that uses Windows Mobile OS may be your best bet.

There are Web sites, such as http://www.smartphone.net, that will give you a variety of software that can be used with your device.

Keyboard
Keyboard styles vary widely, but a QWERTY keyboard is recommended if you will be using your smartphone for lots of data entry or typing. On some phones, the keyboard is hidden away when not in use.

Ultimately, the type of keyboard is dependent on your needs and purpose for which you will be using the smartphone. In some models the keyboard serves a number of functions.

Some smartphones use styluses which can make navigation easier than typing.

Memory
To get the most out of your smartphone, opt for one with memory that is 6MB or more and definitely get one with an expansion slot. These expansion slots help to increase memory when needed in addition to facilitating the transfer of files and even applications that you may need to use periodically.

You will need as much memory as you can get if you are into multimedia and music.

Camera
A camera of 2 megapixels or more is generally ok for most smartphone users, since it is unlikely that this will be used for really professional jobs.

Email access
Email access may be important depending on whether or not your smartphone will be used for work. Windows Mobile OS is good for those persons whose employers IT departments use Microsoft Exchange Server for email.

Screen
Since the smartphone is so much more than just a phone, a large screen is best. For those of us who use the smartphone to write or read a lot, a small screen will impact productivity and pleasure of using this device.

Getting a color screen is a no-brainer these days since the technology is so cheap just about every phone has a color display.

The phone plan
Because they need both Web surfing and phone calling capabilities, it is important to get the best plan in terms of cost and service for your smartphone.

Other thoughts
One additional feature that should be looked at is wireless connectivity, such as BlueTooth, infrared, or WiFi. The more wireless options you can get with your smartphone, the better. Make sure that the smartphone has a USB port. making it easier to transfer data to and from your computer; this is especially important if you use the device for work purposes.