-- Encrypt and authenticate at the server. All sensitive data stored on the enterprise network needs to be encrypted to prevent theft particularly in the case of physical compromise. Similarly, one needs to authenticate before access to the data is granted. I'm a big fan of two-factor authentication; hardware tokens will become much more cost-effective over time, and I expect they will become the norm.

-- Encrypt and authenticate at the client level. Similarly, and I know this is a pain, any mobile device holding sensitive data must also encrypt that data, and users must authenticate with the device. Entering a PIN is a pain on cell phones, but it's necessary in many cases.

-- Use VPNs everywhere. Finally, use a virtual private network to ensure that data is secure end to end. I think Secure Sockets Layer VPNs will dominate as Web services become the norm, but there are many good choices available.

Using the above philosophy, data can appear in the clear only to authorized users, and the theft of information and unauthorized access become very difficult indeed. Of course, there is no such thing as absolute security, but the above works pretty well.

Note also that during the WEP era, our primary concern was the casual hacker, who was trying to get into networks for reasons of mischief, bragging rights, intellectual curiosity or a pathological need for Internet access. The real threat is the professional information thief, who gets paid to commit crimes and isn't likely to be found within range of an access point with a Pringles-can antenna, waiting for the top-secret strategic plan to come flying by. Rather, they're going to look for weaknesses elsewhere in your network value chain. That's another reason I like the above approach -- it's end to end. And as a bonus, it will work with any network, including wide-area wireless services.