Minimize downtime when changing IPs of a single or multiple accounts.
It is well known that changing the IP of a site will make it unavailable until the dns cache expires.
This "unavailability" has been successfully avoided manually by creating a manual httpd.conf entry with an duplicate apache virtual host on the old ip as well and then once the cache expired, deleting the old virtual host.
To handled this elegantly a temporary virtual host would need to be set up that gets deleted after a custom time, like 24 hrs usually is enough. This way, changing the ip address of a site would not cause any downtime because the server would respond on both IPs for the same domain.