[Bluecobra]

>If you disable ARP, you can have a group of servers on the same network configured with the same IP!

The downside to this is that a switch/bridge will not learn the MAC address and continue to flood/broadcast these packets to every port in that segment. So if you do decide to do this make sure you make a dedicated VLAN. :)

[10000truths]

ARP is for the LAN devices. L2 switches don't rely on ARP to build up their forwarding tables, they can just inspect the source MAC of every Ethernet frame they receive, and correlate it with the port they receive it on. Frames with unknown destination MACs are broadcast, but that stops as soon as every device in the LAN has sent at least one frame.