The cops who came before you had to rely on plastic-coated reference cards and notebooks stuffed in their shirt pockets, and maybe you do to some degree as well. Still, there's no reason not to take advantage of the amazing and relatively cheap computing power of a smartphone to use while on patrol.
The line between smartphones and other cell phones is increasingly blurry. It's rare to find a cellular handset that only makes and receives phone calls anymore. Virtually all of them incorporate cameras, can send and receive text messages, and incorporate some multimedia or information storage capabilities. The primary advantage of smartphones is in the ability to install programs or applications ("apps") of your choosing, and not be limited to those that came with the phone.
Which apps are available to you is largely determined by which phone and carrier you choose, and which operating system (OS) you run. The most widely used operating system is one you may not know, called Symbian. Symbian runs exclusively on Nokia phones, and has almost 50 percent of the market share worldwide. The reason you haven't heard much about it is that "worldwide" in this case means "besides the United States." In the U.S., BlackBerry is king, followed by the iPhone, Windows Mobile, Android, and Palm. Of these, Android is the comer, expected to pass iPhone's iOS by 2012.
Fortunately, you don't have to plan that far ahead. Most smartphone users trade out their handsets at least every two years, if not more often. The technology evolves so quickly that the hottest phone on the market today will be passé in two years, and the new app you will want to use won't run on the old one. If you're not already using a smartphone, this is a time to live for the moment. Find one that suits your immediate needs, and don't be too concerned about growing into it.
Messaging and E-Mail
Your world may already run on e-mail and text messaging. To whatever degree it does, you will want a phone that is compatible with the messaging conduits you use. Do you need to access more than one e-mail account (such as your personal and work accounts)? Most phones that are e-mail capable will communicate with personal e-mail services, but many corporate and government e-mail systems use enterprise servers that require special protocols.
This is the reason that BlackBerry rules the business market for smartphones. Research In Motion (RIM), the company that owns BlackBerry, runs its own servers and plays nice with enterprise systems. Most BlackBerrys have hardware keyboards with physical keys, rather than icons on a touchscreen, and are optimized to "push" messages to the handsets without the user having to request them manually. Other smartphone systems will do this, too, but RIM has the most transparent setup for it.
Text or instant messaging (IM) works on most any cell phone, but the hardware vs. software keyboard issue can be a critical feature if you use IM a lot.
Where possible, try using a handset in the store before you make a purchase. A tiny difference in size or the placement of a few keys makes one handset a pleasure to use, where another makes your hands and wrists ache.
Whichever you choose, remember that you're no longer a spectator in the world, and you can't afford to lose situational awareness while you compose an e-mail or IM. Restrict that activity to environments where you're relatively safe, or when someone is watching out for you.
Smartphone cameras have some serious chops these days, and there's every reason to make use of them. Photos document information in a way words can't, and you never know when something that seemed trivial yesterday will be important today.
When you check out your car at the start of watch and find there's a ding or two in the paint, take a picture. It might save you some grief later. When you notice that homeboy has found an innovative method of lacing up his sneakers, take a picture of it. That could be the only distinctive detail his next robbery victim remembers about him. Photograph new graffiti (so you can tell when it becomes old graffiti later in the day), cars of people you stop, and storefronts of businesses on your beat. You'll learn them faster, and have a record of what is typical for the business, and what isn't.
Most every cop I know who has made it through his career wishes he had more pictures from "back in the day." Take pictures of the people you work with and the things they do. Make sure you record the names of the people in those pictures, because, trust me, the day will come when you won't be able to remember them. There is commercial software to help you index and document your photos, but the free Picasa application from Google works about as well as the others.