I created a dir /mnt/vfat. Then with the command
$ mount -t vfat /dev/hda1 /mnt/vfat
I can go straight there. I do this as root because I do it so rarely, but you can modify your /etc/fstab and make it available to all users.
I've never tried to write to the windows partion, and I understand that this is a no-no if you use ntfs. But just reading my fat partion has not caused any problems.
You can read more about it with $ man mount
Also see these linuxquestions threads:
ntfs?
How to mount ntfs partiion