I have a folder on the SBS 2003 server where I want users to be able to edit files, but not move or delete them. The files are in Excel. When I removed the delete permission, I couldn't save the files. I assume this is because Excel deletes the original before writing the new file. I don't care about the possibility that they select everything in Excel and then hit delete - the deletion and/or moving of the files appears to be accidental.
thanks for the answers, I hadn't thought of using Sharepoint - Shadow Volume has kept me sane so far