I've got my laptop set up to boot either eCS or Windows. To share information between the two operating systems, each must be able to access the same drive.
One way is to use the FAT 32 file system. While booted to eCS, I created a 1 GB volume in LVM. Then I booted Windows, and formatted the volume FAT32. The system uses the same drive letter in both Windows and in eCS, thanks to disk manager in Windows and LVM in eCS.
This method is seamless for both operating systems, but takes a 1 GB chunk out of the available hard drive space.
Using NetDrive and the NTFS plugin, I was able to mount the Windows boot drive for read/write. The problems are that move and rename are not supported and can cause corruption. In addition, the NTFS drive must be unmounted before shutting down or Windows will CHKDSK on its next boot.
If you can live with the limitations, this looks like a more efficient solution that the FAT32 method.
If you happen to have an external drive, formatting it FAT32 can give you a nice sharing mechanism. The drive should be prepared with LVM, and formatted with Windows. In both operating systems, you should remember to eject the drive before removing it, so the file system will be cleanly closed.
By far the best solution is the network drive. If you have an available file server, be sure to use it rather than any of these methods.