Three things to do:

1. Make darn sure any securities account you have is not a margin account. If the firm with which you have the account goes bust, the margin account holder is at risk of being a general creditor. Why? Because the margin account allows the securities to be loaned out and traded by others, this is needed by short sellers. But if it goes bust when what you own is loaned, you get screwed. NO MARGIN ACCOUNTS. See: http://www.bogleheads.org/forum/viewtopic.php?p=243626&highlight=

2. FDIC protection runs to $250K. If you have more, then spreading the money out among banks will spread out the risk and potentially get you more protection. Also, a married couple can get protection on three accounts by having one in each person's name and a joint account. All three would get FDIC protections, as I understand things.

3. Have cash. I know of major bank employees who recently having been maxing out their ATM wthdrawals every day. If banks have runs, having cash is going to be good. Banks in NYC have almost no $100 bills. Lots of people ae hoarding cash too.