Many of today's most popular smartphones can be erased from afar if they're misplaced or fall into the wrong hands. Here's how to do it.

Our phones are valuable, but they're easily replaced. The data on them, however, is often much more important. Cell phones carry all kinds of personal and business information these days, so preventing them from getting in the wrong hands is key.

While a stray personal address book won't matter much to an unsavory type who finds a lost iPhone—they'd much rather just sell the phone—cached online banking passwords, corporate documents, and VPN access are better off kept secure. That's why many of today's smartphones support a mobile kill switch, also called "remote wipe" capability. Remote wipe lets you or an IT employee remotely erase the handheld's data in case it's lost or stolen.

All of the major smartphone platforms have some kind of remote erase capability. There are several ways of doing it, such as installing apps on the handset, using a management console on the IT side, or signing up for a cloud-based service. Here's a rundown of what's out there for each platform. No matter which smartphone OS you or your employees use, you're bound to find something that can help put your mind at ease.

The good news is that the same features that enable the remote disable can also just be used to find the phone. Most of today's smartphones have some form of GPS capability. That means you can use the same tools just to find or locate the lost phone in the first place—and potentially, depending on who has it, or where it's found, get it back.

Which brings us to our last point: Though it varies by platform, the remote wipe solutions listed below—or any for that matter—aren't fail-safe. If someone finds the phone before the remote wipe occurs—which could happen if the battery dies, or there's no signal to receive the command—a thief or corporate spy could disable the network connections and then hack away. Your best insurance, therefore, is to disable the handset as quickly as possible, the same way you would call your credit card company the moment you noticed a credit card was missing.

Apple iPhone

Thanks to iCloud, you can now locate and remotely erase any iPhone. While you still have the device, head to Settings > iCloud and turn on Find My iPhone if it isn't already enabled. If you lose your phone, you can find it either by installing the free Find My iPhone app on another iOS device, or by visiting icloud.com, signing in, and using Apple's Web-based Find My iPhone app. With either tool, you can remotely lock the phone with a passcode if you haven't already, send a message to it, play a sound, or remotely wipe the phone.

Google Android

Android Lost adds remote find and wipe capability, and also lets you set a password and lock the SIM card slot. You can even sound an alarm when the phone is on silent—perfect for finding it when it's buried in the couch cushions. We're particularly fond of Android Lost because you can push the app to the phone from Google Play (formerly the Android Market) remotely. In a corporate setting, IT managers deploying Android devices can enable native remote wipe capability by installing Google Apps Device Policy, though it can't be added retroactively.

Microsoft Windows Phone

For any Windows Phone 7 or 7.5 device, head to www.windowsphone.com on a desktop or laptop PC and sign in. Then click My Phone. From here, you can locate the phone with GPS, erase all the data, lock the phone and display a message, or change your password. Microsoft also lets you set the phone itself to save its location every few hours; this helps if you lose the phone later and the battery dies, since it will have reported its last known location. To do so, head to Start > App List > Settings and tap Find My Phone.

RIM BlackBerry OS

Research In Motion offers BlackBerry Protect, a free app that lets you find, lock, or wipe your BlackBerry from a remote location. It also adds daily, weekly, and monthly backup capability for your data. Any BlackBerry Enterprise Server (BES) handset can be erased remotely via the Erase Data and Disable Handheld IT administration command over the wireless network. IT admins can also specify if the handset should revert to factory default settings or retain the IT policy it had before.

For more on protecting your phone, read The Best Mobile Security Apps.