If you're like me (forced to use Wind-bloze at work while using all Macs at home), you may need this to transfer files back and forth using NTFS (not this f*cking sh*t) drives. Modern Macs can read pure NTFS volumes but can't write to them.
Recently Amit Singh, a Google employee, releases a implementation called MacFUSE which makes it possible to use any FUSE (File-system in USErspace) file systems in Mac. And the most useful FUSE is the NTFS-3G Read/Write Driver, which ables system to load NTFS with read and write capability. This is truly the greatest news for dual booting Mac OS X and Windows XP or Vista.
[From How-to: Read and Write NTFS Windows Partition on Mac OS X]