FYI,
I'm going to have a talk at JBossWorld / Red Hat Summit 2013 in Boston on June 13: http://www.redhat.com/summit/sessions/index.html#54.
This will be about a feature in JBoss Data Grid (JDG) which provides geographic failover between sites. I'm going to run a couple of JDG clusters (Boston, London and San Francisco), and initially route all clients to London. Then, as London shuts down at the end of their day, I'll route all clients over to Boston, and finally to San Francisco.
I have a demo that can be run by anyone with internet access, in their browser. Users can punch in some data, and will see their clients fail over between sites seamlessly, without data loss.
Hope to see / meet some of you in Boston !
Cheers,