Mirror is actually the hardest part of the code, and honestly I never use it, so it will probably be disappearing from any future builds. The idea is to remove any files and folders in the destination that do not exist in the source. If you rename a file, or even just delete one, the Mirror function would remove that from the destination, since it no longer exists in the source. Kind of a housekeeping operation. As for the online backup, that depends on where you save your online files. My web host (HostGator) has some sort of feature where you can set up a mapped drive to their server, as does Mozy and Jungle Disk. So, as long as your online storage provider gives you a drive letter you could use this with no problems. If you wanted to do something more like FTP, there are plenty of UDFs with FTP support, and you could do something like: Generate an MD5 hash for a file Save the file name and the MD5 to a database Compare the MD5 from your file to the MD5 on the server Update if the MD5 is different. Thanks for the comments. Ian