In addition to Bootcamp and Parallels, there's another option for those wanting to run Windows applications on their new Intel-based Macs.
CrossOver Mac from Codeweavers promises the ability to run Windows apps on top of Mac OS X Tiger, without having to install Windows XP.
Once installed, your application integrates seamlessly in OS X. Just click and run your application directly from the OS X Finder. Clicking a Windows file or document — including email attachments — will launch the appropriate Windows program, allowing you to work on the files. Best of all, you do it all easily and affordably, without needing a Microsoft operating system license.
Seems really too good to be true, and in fact it probably is. CrossOver is emulating Windows XP and while I'm sure it's passable with some of things like Word or Excel, I don't think I would try to run Photoshop on it. This product comparison chart also indicates that some, but not all, Windows applications will run on CrossOver and that "minor performance penalties may occur."