Please not - BIG disclaimer - FLASHING - I don't believe this is supported. Read and apply at your own risk....
http://nyc-dba.blogspot.com/2008/10/using-local-disks-in-cluster.html
The key pieces of information are in the comments section.
David
@SQLTentmaker“He is no fool who gives what he cannot keep to gain that which he cannot lose” - Jim Elliot