As it turns out, one of the last big bastions of incompatibility is the file system. Windows machines can't do anything with the Mac's Hierarchical File System (HFS). However, Mac's can read Microsoft's NTFS format. But they can't write to the NTFS disk.
Both platforms do support the FAT32 file system. However, when you are dealing with large files, for example home digital video, FAT32 is lacking. FAT32 supports a maximum file size of 4Gig. So that hour video you made that is 11Gig ends up getting truncated. So, how do we get the files from the Mac to the PC?
I tried FTP - way to too slow and timed out eventually. Also, tried sharing the PC disk and making an SMB connection from the Mac to the PC. However, it looks like there is the same 4Gig file size limit in the SMB software.
What I ended up doing was putting the video files on a Mac formatted portable drive. I then took the portable drive to the PC and used a piece of free software called HFSExplorer. With this software I was able to open the Mac volume and "extract" the files to a local NTFS drive. It worked great! I started it running before going to bed (45Gig to run through). Although after only a couple minutes it had already "extracted" over a gig. Much faster than any of the other methods I had tried.
I used HFSExplorer on a Windows XP machine. However, it is written in Java so it should be useful on other platforms as well.