Howtoforge posted a guide about enabling NTFS write support (ntfs-3g) on Ubuntu Feisty Fawn

Normally Linux systems can only read from Windows NTFS partitions, but not write to them which can be very annoying if you have to work with Linux and Windows systems. This is where ntfs-3g comes into play. ntfs-3g is an open source, freely available NTFS driver for Linux with read and write support. This tutorial shows how to install and use ntfs-3g on an Ubuntu Feisty Fawn desktop to read from and write to Windows NTFS drives and partitions.

How To Enable NTFS Write Support (ntfs-3g) On Ubuntu Feisty Fawn