Our company is moving to Windows Server 2003 and, thus, IIS6. One business unit is toying with the idea of standardizing on load balancers or at least fail-over clusters. One problem is testing that in development environment without incurring the cost for the extra equipment.
I happened across a posting by Eric Bowens that has a low cost solution: Change the Web Garden setting from 1 to 2, which round-robin's request between two isolated applications. Sweet!