You have a beautiful new Intel Mac but you need Windows for those apps that cannot run on a Mac. Not a problem. Buy a copy of Parallels Desktop 4.0 plus Windows XP or Vista or Linux. By the way, Windows 7 is due to come out this summer (2009). If you are a new Windows-on-Mac user and have licenses for apps that you have run on a Windows machine, you can continue to use those software licenses and do not need to spend money for a Mac version.

Parallels Desktop is an essential application for Mac users who work in Windows. Many new features have been added since my review of its earlier 3.0 version. Its remarkable virtual operating system density, low virtualization overheads and outstanding management have earned it several awards and I highly recommend it. Its best feature is that it allows you to run Windows on your Mac without rebooting. It's also fast due to its new improved virtualization engine. It supports 64-bit Windows with up to 4 CPUs and 8GB of RAM.

Compared to Parallels 3, in which installation was a truly horrible experience, this installation was refreshingly easy. You can install Windows XP or Vista without any fuss. I installed Windows XP. I immediately liked the interface but changed the background wallpaper to one of my favorites — a beautiful island scene surrounded by clear blue water.

I copied and pasted text and shared files easily between Mac OS X and Windows. When I connected my GPS, Parallels asked whether I wanted to attach the device to my Windows environment or my Mac environment. When my system detected the iPhone, it popped up a window asking me whether I wanted to attach the iPhone to Windows or to the Mac. I chose the Mac, and the iPhone automatically started synching normally with iTunes on the Mac.

There are several ways to access Windows and the Mac OS--Full Screen, Window, and Coherence. All of these modes existed in Version 3. Version 4 adds another mode called Modality in which the Microsoft OS desktop can be made very small, and partially transparent, while completely preserving all the details of the full desktop. This is designed for operations that can run mostly unattended, but which you need to keep an eye on (such as installing the latest Windows Service Pack). It may come in handy at times.

To secure your data, you can take snapshots of your Windows configuration and roll back to those images if necessary. You can also program the app to take snapshots automatically at half-hour intervals. This is analogous to Time Machine Lite since it provides a way for Windows to preserve statuses.

Another feature is Safe Mode. When activated, Parallels takes a snapshot. You can make changes and then can save or revert to the snapshot.

With this version you get one free year of Parallels Internet Security by Kaspersky. I installed it. You also get Acronis Disk Director Suite for disk management, and Acronis True Image Home for backup. The included User Manual is very helpful.

I did not do any scientific speed tests, but from my experience with older versions, this version has a significant speed bump. There were fewer spinning beach balls when opening apps.

If you're a Mac user running Leopard, use Spaces. Keep Parallels in one Space and your Mac OS in another. With a key combination you can switch workspaces and you don't have to worry about minimizing windows or hiding applications.

There are other choices to run virtualization software on your Mac: VMWare Fusion ($80), and VirtualBox v 1.6.2 (free).

My recommendation: If you're a power Mac user, this is not going to satisfy you at all. You cannot run Windows games. If you do, they will run slowly. A better solution to have the full benefit of your Mac hardware is to install Windows via Boot Camp. And no matter what you need Windows for, you have to worry about viruses. I spent a lot of time running the Anti Virus program when it indicated that I had 3 security risks.