CLUSTERIP is in patch-o-matic-ng
About one year ago I did some work for SuSE in implementing load-balancer-less load-balancing clusters ;) This is achieved by replying to ARP requests with a link-layer multicast address, so all nodes receive all packets. Hashing parts of the ip header now determines whether the packet is to be passed up the stack on a given node.
The result is called the iptables CLUSTERIP target, and I've now finally put it in patch-o-matic-ng, since it was only available in my undocumented public CVS tree so far.