Snow Leopard has the ability to mount NTFS volumes as read/write, but it's not enabled by default -- just read only is supported, as in 10.5. Here's how to get full read/write support for NTFS drives in Snow Leopard. First, uninstall NTFS-3G or Paragon if you're using either one.
Here's how to get read/write support for NTFS drives in Snow Leopard:
1. In Terminal, type diskutil info /Volumes/volume_name, where volume_name is the name of the NTFS volume. From the output, copy the Volume UUID value to the clipboard.
2. Back up /etc/fstab if you have it; it shouldn't be there in a default install.
3. Type sudo nano /etc/fstab.
4. In the editor, type UUID=, then paste the UUID number you copied from the clipboard. Type a Space, then type none ntfs rw. The final line should look like this: UUID=123-456-789 none ntfs rw, where 123-456-789 is the UUID you copied in the first step.
5. Repeat the above steps for any other NTFS drives/partitions you have.
6. Save the file and quit nano (Control-X, Y, Enter), then restart your system.
After rebooting, NTFS partitions should natively have read and write support. This works with both 32- and 64-bit kernels. Support is quite good and fast, and it even recognizes file attributes such as hidden files. My thanks go to Chrysaor, a MacRumors user who brought this to our attention.
[robg adds: I haven't tested this one, as I don't have any NTFS drives on my Snow Leopard machines. There may be good reasons why Apple left support disabled, so use at your own risk. Mac OS X Hints reader Jakimowicz submitted a similar hint which pointed out the free NTSF Mounter utility, which lets you enable read/write on NTFS volumes via a simple GUI.]
