SQL Server in CLuster

Sure, but remember that a cluster in Windows is for redundancy, and load balancing. In Unix it provides increased processor power (Beowulf Cluster).

For more info:
http://www.microsoft.com/windows2000/technologies/clustering/default.mspx

Job Cacka

Yes clustering can be simulated.
I recommend using Microsoft Virtual Server 2005 as detailed in this tutorial. http://www.sql-server-performance.com/installing_sql_clustering_virtual_server1.asp
I'd recommend at least 128 MB of RAM allocated for each node in the SQL cluster to get some better load performance measurements.

I've done this in a lab environment using 2 machines with 4 nodes(virtual) for 2 different clusters successfully.
It (MS Virtual Server) is great for testing purposes but Microsoft nor I recommend it for production use.