Microsoft has released a new update for Windows Server 2003 two add two new (separate) functions to clustering.
The first is File Share Wintnessing. This adds another form of "communication" between two nodews of a cluster, thus preventing a split brain scenario or a situation where a fialover nodes uses incorrect cluster state information when it starts up.
The second feature enables configuration cluster heartbeats. One size does not fit all so this functionality allows you to configure heartbeats according to your network or requirements so that unwarranted failovers do not take place.
There’s heaps of documentation on the Microsoft Support page so I’m not going to bother copy/pasting or re-interpreting it. I’ll let you read it for yourself.
It requires Windows 2003 SP1 or Windows 2003 R2. Obviously your OS must support clustering (Enterprise or Datacenter editions only). Be sure to test this update before you deploy on valued systems.