Heartbeat/Pacemaker help?

[jetboy]

Anyone had any experience setting up high availability Linux clusters with Heartbeat and Pacemaker?

I'm attempting to setup a redundant pair of Ubuntu VMs running Varnish as a reverse proxy/round robin load balancer. I think I might end up a little out of my depth with the Heartbeat/Pacemaker stuff, particularly the provisioning of a shared virtual IP. Does anyone have the expertise and willing to field a few questions?