During a home health visit last month in Oklahoma City, a nurse for Integris Health was held up at gunpoint. She escaped unharmed, but was robbed of her company-provided laptop and cell phone. Both devices held sensitive patient data, but Integris wasn't worried. "All of the sensitive files were encrypted," says Randy Maib, senior IT consultant at the company.

Integris uses Credant Technologies' Credant Mobile Guardian software, which provides data encryption for all sorts of mobile devices. "We feel comfortable that we've ensured the protection of our data - which is good, because you never know what's going to happen."

Read related stories on keys to mobile security and a mobile security wish list, and download a sample acceptable use policy. 

Indeed, securing data on mobile devices, especially as storage capacity grows and size shrinks, is becoming a particularly thorny problem. Vendors have begun addressing the problem, but few provide centrally managed, soup-to-nuts security. With that in mind, here are five basic steps you can take to make sure your mobile data stays safe.

1. Know what to secure

"You have to understand the type of data people are going to access and the risks associated with that data," says Jack Gold, founder and principal analyst at consulting firm J. Gold Associates. "You don't care if an e-mail about three kittens for adoption gets lost. But you do care if it's an e-mail talking about customers or financial issues with Social Security numbers and bank accounts."

Roy Balkus, CIO at Naugatuck Savings Bank in Naugatuck, Conn., takes this advice to heart. After deciding which users need peripherals, CD drives and USB devices, he uses Centennial Software's DeviceWall to control how much access and what type - read-only or read/write - they get. In addition, he provides full hard-disk encryption for mobile laptops. But he doesn't encrypt PDAs or mobile phones. The bank's acceptable-use policy spells out that no confidential or sensitive customer information can be stored on any portable handheld device without IT's permission. "People mainly use PDAs for contacts and calendar. Our business model dictates where we focus the security," he says.

Similarly, Integris' Maib uses Credant Mobile Guardian for file-level encryption, choosing the files to be encrypted according to their sensitivity. Credant provides a central console from which Maib can encrypt based on common file-types. "We're sure security is going where it's most needed," he says.