Primitive failover. (Not load balancing)

[Aaron Roberts]

Hi all,
	I am looking to setup a really simple manual
(potentially-involving-human-beings) failover for a website served by
webservers at geographically and BGP A/S seperate locations.  I've =
decided
the failover mechanism will be a change of IP for the www A record, so I =
want
a really low TTL on that A record.

I figured that a TTL of '0' might be misinterpreted by caches and =
decided
that 60s would probably be about right but I simply don't have the =
experience
to make a sound judgement myself..  So my question is: What would be the
lowest 'safe' TTL that I could give the A record?

Many thanks,
	Aaron