Another alternative if you just want to share your files in a dual-boot system between Windows and Linux is to partition the HD 3 ways (at least)
hda0 :NTFS (Windows)You can re-direct your My Documents folder to go off of the Fat32 partition by right-clicking on My Documents and go into Properties. You will see a place to put the location of My Documents and you can redirect it to the drive letter.
hda1 : EXT3 (Linux)
had2 : Fat32 (files)
If you share the computer with multiple people, you may want to set up a sub-folder with each person's login name and set each of their My Documents to their specific folder. Of course Thunderbird allows you to redirect where you want to keep your files.
One thing you'll notice is that Windows allows you to set a file or folder to be hidden.. Linux doesn't hid them. Linux instead uses the prefix "." (like .Trash ) to hide the directory of file and you guessed it: Windows shows those.
Also note, this doesn't move over Application settings (like default Mozilla Thunderbird files go in C:\\Documents and Settings\<<your login>>\Application Date\Thunderbird and this is NOT moved to the Fat32 Partition in this example, only the things under the My Documents folder.
An alternative of this, though, is to set up the Fat32 partition as an "( S: )" drive.. for "Share". This way you only put those files you want to share between the OSs there and everything else stays in the default location.
On the Linux side, all you need to do is
Mount the partition (modify the /etc/fstab file, or check the Disk Management tool)
Symlink to the mount point to make it easy to access (middle-click the mounted directory and drag it to where you want it and select "Link"
The nice thing about that is that for all intents and purposes the link IS the linked directory so all navigation, etc. is as if those files are in the link, not in the actual directory. I wish Windows Shortcuts would work like this.
I do not recommend linking your entire /home/ directory to the Fat32 partition. Even if it works (which it did for me) it caused me errors, and after seeing a partition table I built using a Live CD get blown away when I booted windows because it didn't understand it (or something), I am hesitant on having crucial information placed where both can access, and so suggest the Shared directory method instead.
Another alternative is using VMWare and setting one up as your host, and the other as a virtual machine and sharing (if that is possible) the desired directories ( or the whole C: ).