Can you run Windows "inside" MacOS X on an Intel-based Mac?

Yes, using a "virtualization" solution like Parallels Desktop for Mac or VMWare Fusion.

Parallels rightfully boasts that:

Parallels Desktop for Mac is the first solution that gives Apple users the ability to run Windows, Linux or any other operating system and their critical applications at the same time as Mac OS X on any Intel-powered Mac.

Unlike dual-boot solutions, in which users must completely shut down Mac OS X and endure a full OS start-up cycle to access a important application, Parallels Desktop for Mac empowers users with the ability to run Windows programs. . . without having to give up the usability and functionality of their Mac OS X machine even for a few minutes.

Parallels Desktop for Mac supports effectively every version of Windows, as well as Linux, FreeBSD, OS/2 Warp, eComStation, Solaris, and MS-DOS "in secure virtual machines running alongside Mac OS X" and provides "near-native performance", rather than the full speed of a "dual-boot" configuration.

If you have modest performance requirements, you also might want to try Q, which runs "on top of" the QEMU emulator and allows versions of Windows to run "inside" MacOS X.

As of the date of this writing (see top), the Q website notes that "Windows 95 B, Windows 98 SE, Windows 2000 Professional SP3/SP4, and Windows XP SP2" are now stable "recommended" operating systems. Even with the release of Parallels Desktop for Mac, it's well worth checking out. It's an emulator, and consequently, slower than a virtualization solution, but it's free.

Another solution for running some Windows applications "inside" MacOS X, without running the Windows operating system, is CodeWeavers CrossOver Mac. CrossOver Mac is not compatible with all applications, but it does not require one to purchase a copy of Windows either.

Can you access Mac files from within Windows?

When booting Windows via Boot Camp, yes, by purchasing and installing a program like Mediafour's MacDrive 6.

Mediafour advertises that "MacDrive 6 for Windows enables PC users to open, edit, and save files on Mac disks (HFS/HFS+). You can even format Mac disks and burn Mac CDs and DVDs."

MacWindows provides additional information regarding conflicts and workarounds for MacDrive that you also may find helpful.

When using Windows via Parallels Desktop for Mac, you can easily share files between operating systems using the "Shared Folders" tool, or starting with beta 3036, with "drag and drop" convenience. The beta of VMWare Fusion also has drag and drop capability.

Can you access Windows files from within MacOS X?

In a "Requirements, Installation, and FAQ" document at the Apple Support Site, Apple notes that "Mac OS X can read and write FAT volumes, but only read NTFS volumes".

Just like you previously could using the "XOM hack", if you create a FAT32 (MS-DOS) partition using Boot Camp of 32 GB or smaller, MacOS X can access, read, and write to files on the Windows partition.

When using Windows via Parallels Desktop for Mac, you can easily share files between operating systems using the "Shared Folders" tool, or starting with beta 3036, with "drag and drop" convenience. The beta of VMWare Fusion also has drag and drop capability.

Can you "copy and paste" between MacOS X and Windows?

Not with the original "XOM hack" solution or Apple Boot Camp, but with Parallels' Desktop for Mac you can "copy and paste" between MacOS X and Windows using the "Shared Folders" tool, just like you can using Virtual PC on PowerPC-based systems.