Imagine if someone were to steal your laptop, PDA or cell phone. Your credit card numbers, banking information, telephone numbers and other personal data could be disclosed. Today, you can destroy that data remotely.

If your laptop is stolen, you can notify a service. The software on the stolen laptop continually runs in the background. When the computer goes online, the service sends a signal to destroy the data.

The crooks still have your laptop, but your personal information is safe. These programs claim to be undetectable.

Absolute Software's Computrace Data Protection (www.absolute.com; $70) and Novell's ZENworks (www.novell.com; $130 and up) are designed primarily for businesses with information technology departments. They are too complex for the average computer user.

Consumers can turn to zTrace's zControl (www.ztrace.com; $40 and up). Say your laptop is stolen. You would call, e-mail or fax zTrace.

The software would mark your laptop as stolen. The next time the thieves go online, files would be deleted. zTrace also has the ability to lock the laptop's keyboard and mouse. And it can display a predefined message to the thief.

There's also Computrace's LoJack for Laptops (www.lojackforlaptops.com). It contacts a monitoring center when the laptop connects to the Internet. If your laptop is stolen, you notify the police and Computrace.

When the thief connects to the Internet, the signal sent from your laptop is used to determine its location. The company sends the location and documentation to support a search warrant to law enforcement. LoJack for Laptops starts at $50 for a year term.

However, these programs only work if the thief connects to the Internet. They cannot prevent a thief from mining the laptop itself.

That's why encrypting data is important. Microsoft's Windows XP Professional and Apple's Mac OS X have built-in utilities that do this. It's easy.

In Windows XP Professional, right-click on a file or folder and select Properties. On the General tab, click Advanced. Select "Encrypt contents to secure data" and click OK. Click Apply and select your options. Click OK.

FileVault is available in Mac OS 10.3 and later. Click Apple, then System Preferences. Under Personal, select Security. Click Set Master Password to set a password. Click Turn On FileVault.

But your laptop isn't the only danger. PDAs, which often carry personal and financial information, are easier to lose or get swiped.

PDAKill ($10; Pocket PC) and remotePROTECT (Pocket PC 2003 and Windows Mobile 5; $15) allow you to establish a special word or phrase. If the phone or hand-held is stolen, you send it a text message from another machine. Both programs are available at www.scpsoft.com.

Included in the text message is the kill word or phrase. The phone or hand-held is returned to its original factory condition and any personal data is erased. The programs will also delete data from any storage cards installed.

For Palm Treo owners, there's Central from Bluefish Wireless (www.bluefishwireless.com; $15). This suite of utilities includes Kill Pill, a program that also erases all data after receiving a text message with a kill word.

Contact Kim Komando at gnstech@gns.gannett.com.