How to Pass Multi-Valued Parameter to SSRS Sub Reports

I'm working on a report that contains about 10 subreports. Some of the subreports need multi-valued parameter passed from the main report. After struggling with it for awhile I came across a good post that explains three different ways to do that. All three worked from me.
http://social.msdn.microsoft.com/forums/en-US/sqlreportingservices/thread/ae5ac615-1076-428d-9fcf-6c27e5fee1f0/

Create a Report of the Reports

After some digging, I found this post that talks about how to get report usage information:
http://p2p.wrox.com/content/articles/creating-report-server-usage-report-sql-server-reporting-services