More than a few analyst have made the connection between Vista's UAC and the long-available security and rights model used by the Mac OS X (and Unix and Linux). On the Mac, for example, you're always running as a limited user, but at times -- like when you're installing software -- you have to provide an administrator username and password.
If Vista's UAC is a copy of Mac OS X's approach, why not stare in the horse's mouth.
It means a new computer -- and Apple's Intel-based Mac minis, iMacs, MacBooks, and MacBook Pros are not cheap, no matter what Apple's fans say -- as well as another licensed copy of Windows XP and some virtualization software, but it could be the best of both worlds.
Here's how it might work.
On an Intel-based Mac, install Parallels Desktop for Mac, the $80 virtualization program that lets you run Windows XP and its applications alongside Mac OS X.
Run the most vulnerable software -- browser and e-mail client, perhaps instant messenger client as well -- on the Mac, where they're not only safer because of the system's security strategy, but also safer because threats and exploits against OS X are rare compared to the number that Windows faces.
Work with everything else in the Windows virtual machine (VM).
Copy and paste information, and share files between Mac OS X and the Windows VM using Parallels.
Note: This won't work with Apple's own dual-boot creation too, Boot Camp, because it requires that you shut down one operating system before using the other, and doesn't allow for any file or data sharing between the two.
Bottom Line: Expensive and kludgey, but you get a more secure OS immediately.