What are some of the most popular data mirror programs out there? The only one I know of that seems to fit the bill so far is Double Take and it doesnt have a set price so i had to request a quote (ugh). FolderClone is no good, I need it to run as a service on 2k3 and constantly be running. It doesn't need to mirror things very quickly but it has to do it efficiently, as a background service, and has to work with folders that have a decent amount of activity.
apparently 2k3 has a built in file replication service, however, my concern is that I believe it copies entire files rather than just differentials and is likely to chew up a lot more bandwidth than necessary...bandwidth that i'm paying for.