I made an interesting discovery today regarding the cross-platform use of the TrueCrypt software package. I created an encrypted partition on a thumb drive on a Windows box. This partition used the NTFS file system. But when I mounted this partition in Mac OS X as a non-root user I didn't have write privileges. However, if I created a partition under Windows using the FAT32 file system then I would have write permissions under Mac OS X. My guess is that because FAT32 lacks the extended file attributes needed for per-user permissions.