I've got my cash in a combo of Cal Muni money market and short term US treasuries. Would these be at risk in a meltdown? What would be safer? I was told by one broker that there is no such thing as "cash". It's got to be in some kind of MM at least.
You'll be fine with the Treasurys, as those are the most secured. The California Munis, however, just be sure you're aware that those aren't all insured or guaranteed. Just look at what happened to Sentienal today. Cash accounts usually mean FDIC insured investments. Money Market accounts are FDIC insured, but Money Market Funds aren't. Treasuries are, obviously, backed by the US.