auto-backup across the net

[Kari Chisholm]

Friends--

Here's the situation.  I'm building a mission-critical web-based
database.  It's hosted on a server at, say,
http://www.serverone.foo/bigdata.cgi.

If that server goes down, even for an hour, I want to be able to
immediately tell my clients to switch to another server (at another
location) at, say, http://www.servertwo.foo/bigdata.cgi.

In order to accomplish this kind of seamless transition, I need to
ensure that data is backed up across the net in more-or-less real time
- perhaps, every 5 minutes we ship changes to the data across the net.

Is there an obvious solution or technology that I should be thinking
of?  I'm almost exclusively a Perl guy, so solutions with Perl are a
good thing, but I'm open to other thoughts...

Thanks!

-kari.
TIMTOWTDI