Choosing a new wireless phone can be an overwhelming proposition: There are hundreds of models to choose from; they come in many shapes and sizes; and not all are supported by every carrier.

"Smartphones" can be even more intimidating because they can perform many advanced functions, such as e-mail, Web browsing, music playback, photography, video recording and GPS navigation. Consider them pocket-sized computers that can run hundreds of applications ("apps"), turning your handheld device into the wireless equivalent of a Swiss Army Knife. 

If you're considering upgrading to one of these high-powered devices, the following are five questions to ask yourself to ensure you're choosing the right one for your needs and budget.

1. What will I use it for?

A regular cell phone is ideal for making calls, sending text messages and taking basic pictures. If that's all you need out of a phone, you probably don't need a smartphone, which will require a monthly data fee.

But if you think you'd benefit from accessing your e-mail while on the go, surfing the Web, listening to music or getting turn-by-turn directions, a smartphone might be an ideal upgrade.

If e-mailing is important to you, be sure to pick a smartphone with a comfortable keyboard (see next section). Love surfing the Web? A bigger screen is key. Enjoy taking pictures of the kids or grandkids? Be sure to find one with a good camera.

2. What style is best for me?

Because you're going to be holding this phone quite a bit — for talking, texting or other things — you need to like the way it feels (and looks).

One-piece "candy bar"-style phones don't open up to reveal a keypad or keyboard, compared to "flip" phones that are clamshell-shaped (a design that's found more in regular mobile phones than smartphones). Some users like how you can answer or finish the call by simply opening or closing the phone, respectively.

Some smartphones have a physical QWERTY keyboard — like most BlackBerry smartphones — that are ideal for those who do a lot of typing, be it e-mail, texting or instant messaging (real-time text chats). Touchscreen phones, such as the iPhone, might be less comfortable for those who do a lot of typing as there is no physical keyboard. But they're better for managing your media, playing games and surfing the Web.

Finally, some phones aim to give you the best of both worlds by offering a large screen and a QWERTY keyboard that glides out of the bottom or side of the phone. These are referred to as "slider" phones, but they tend to be a bit thicker as a result. Some of the Android-powered devices (based on Google's mobile operating system) have both a touchscreen and QWERTY keyboard, as does the new BlackBerry Torch 9800.

Never buy a cell phone without touching it first, because you'll need to ensure the keys and screen can be easily seen and touched. The Internet is great for research, but nothing beats hands-on time with products like these.