When you say "convert" filesystems, do you have a magic software utility that will do that for you? Otherwise you've got quite a task ahead. In-place "conversion" from NTFS to ext3 is not something I've seen done before. I have used Partition Magic to shrink an NTFS partition, open up the free space, put the disk on Linux, and format (mkfs) the ext3 partition. But last I knew, Partition Magic didn't deal with non-Microsoft filesystems.
But overall it's MUCH easier and less error-prone to get a separate disk, copy the files to it, repartition/reformat the original disk, and copy back.
Am I correct in assuming that your 250GB NTFS disk has something under 125GB of files on it, so that you can in fact shrink the NTFS partition to half of the physical size of the disk?
That was the plan, reduce the size of the files on the NTFS partition, create an EXT3 partition and move the NTFS files to it, then convert was left and merge them together.
However, I was able to pull up the NTFS drive in Ubuntu, and read the files located on it. I created a file in the text editor, and was able to save it to the NTFS drive. I’m still looking into it to see what all I can/can’t do. Once I get the share up, I’ll see what we can do from a windows box to the shared drive.