We run our entire business on the web.  We host our own web site(s) on
a Windows 2000 server (running Apache/PHP/MySQL) connected to our
local LAN.  We have less than 10GBs of mission-critical data (300MBs
of MySQL data, 7GBs of .PDFs, PHP code, etc) on the server.

We are looking for an inexpensive and ultra-reliable backup/mirroring
service for this data.  We would like to schedule regular and
automatic backups (mirrors, actually) of the data to other machines in
our office (LAN connection), and potentially one or more machines on
dedicated broadband connections outside of the office (WAN/internet
connection).

We currently have an offline, real-time storage option (LiveVault),
but are looking for an option that would allow us to quickly get
another server up and running in the event of a disaster (hardware
failure on the main server, etc).  Our offline backup solution
provides a comfort factor that our data will never get totally lost,
but building a backup server from the offline data would take a day or
more.

Long story short, we're looking for good options for mirroring
critical data hosted on our main server to one or more backup servers,
such that one of these backup servers could quickly replace our main
server in the event of a disaster.  The mirroring does not have to be
realtime, but something close to realtime would be nice.  At a minimum
we're looking for something that performs automatic, hands-off,
mirroring at regularly scheduled intervals.

We have searched for and trialed some software packages (such as
ViceVersa) that supposedly provide some of the logic we're looking for
and aren't terribly impressed.  A software package would work for us,
though, if it is easy to administer and is very reliable.

We're more interested, though, in open source technologies that other
people use in a similar situation -- technologies that are industry
standard that we simply haven't found.  Does Windows 2000 Server have
any built-in backup-to-other-server options that we haven't found? 
Are there open source technologies that can easy do mirroring?

Normally what I did was to have a hardware raid system in place, raid
1 or 5. Windows 2000 supports hardware raid drivers very well. In
addition, I would suggest putting in a totally identical server as
backup server. Make both servers hot swapable. If there is any problem
with the data server, just plug the hard disks into the backup server.
 During normal conditions, the backup server can be used as a ftp
server where you can schedule automatic ftp of the data server into
it.

A RAID solution is probably ideal, but we're not currently set up with
RAID hardware.  For the sake of my question, let's assume that
hot-swappable RAID is not an option.

Regarding FTP-ing all files nightly, we have also tried that route
with limited success.  The problem with FTP is that it's hard to
achieve a true 'mirror' of the data in question.  If files are deleted
from the 'source', FTP doesn't automatically perform the same deletes
on the 'slave'.  FTP is also fairly slow and sometimes flaky.  We're
looking for some sort of software-based solution that's ultra-reliable
and hands-off.

Are you considering your MySQL data is your mirroring idea?  You'll
need to handle database exports as well?

We are familar with performing MySQL backups.  For the sake of my
question, let's treat the MySQL database files as if they were any
other 'file intented for backup' on the server.

Windows Pay Software
I've used http://www.2brightsparks.com/ ($25 though) before.  Don't
know that it's much different than your ViceVersa.

Open Source
--Something more complex is in the spirit on Open Source that I've
also used and it works is http://backuppc.sourceforge.net/

--Install cygwin at cygwin.com and look into rsync over ssh.

Offsite Solution
Ahsay software.  Setup a backup server onsite and have that replicate
offsite.  Or use the backup service like your LiveVault except that
this also has the ability to keep a local file syncronized as well. 
www.ahsay.com or www.peakbackup.com

Thanks for the suggestion of 2BrightSparks' solution.  I downloaded it
and am giving it a trial.  It does look similar to ViseVersa, but
better.  It might meet my LAN backup needs.  I'm not sure if it will
do much in the way of a WAN backup.  We'll see.  The price is
certainly right.

AhSay and BackupPC also look promising.  PeakBackup looks a hosted
backup service, which is not what I'm searching for at the moment.

BackupPC is really LAN oriented too, so maybe not a great WAN
solution.  Good luck....