Three Products That Get The Job Done
There are a number of BMBR products on the market. Products available at small business prices include EMC Dantz Retrospect, Paragon Disk Backup and Symantec LiveState Recovery.
Retrospect backs up to disk and tape, while Disk Backup Professional and LiveState Recovery Advanced Server can only back up to disk. Backing up only to disk is kind of scary, though - what happens if your disk backup becomes corrupt? To avoid losing your one and only disk backup, you can later copy disk backups to tape or other disks. If you're on a tight budget, you can use Windows Scheduler to run a batch file that does the disk-to-disk copies.
One caveat: USB and FireWire external drives are great for disk-based backups and disk-to-disk copies of disk-based backups. However, they tend to run really, really hot. Don't stack the units if you want your drives to last more than a few months. Give them plenty of room to breathe, by assuring there is lots of open space on all sides.
Disk backup is a good thing, especially in small business environments. Generally, backing up and recovering from disk is much faster than from tape, because disk access is almost always faster than tape access. Also, unless you use removable disk media, disk backups are always on-line, meaning you don't have to find and insert the correct tape or tapes.
Each of the three BMBR programs can be set to back up all files the first time you run them and then back up only changes from there forward. This saves lots of disk space. Retrospect and LiveState Recovery are able to automatically prune their backups, eliminating older backup files. You can't go back as far in time with pruning, but this can save large amounts of disk space.