Nu2,
For IRA/401k type accounts, you can only look to re-balance based on the options available to you in your plan or with your broker (Fidelity/Schwab/etc..).
I am by no means a certified financial planner, and there are likely some better options that the ones I will lay out (ScottL for example got into a Exchange Traded Fund that benefits if financials as a sector drop - has done nicely).
The options I would consider for simply PROTECTING principal at this time would be short term T-Bill options or TIP(Treasury Inflation Protected Securities).
T-Bills are the option on the shorter term 4,13, 26 or 52 weeks.
You will not find much in the way of return at this time (maybe 1.5%), but will keep what you have. Many may argue that due to inflation, you will actually be losing money in these investments, and if you were looking at these as a long-term investment strategy, I would agree. Personally, I wanted to keep what I had, and then be able to evaluate other potential investment opportunities on the 'other side' of this.
Many seem to think that as the quest for capital increases (municipalities, corporations, the treasury, etc...) that yields offered will climb to attract the $$. Other investment opportunities would also likely evolve, however, I don't believe that the 'general market' will provide more than single digit returns for what may be 15+ years going forward.
As for us, wife's 401k had a TIPS option, we took it. My 401k added an option for T-bills, we took it.
Rollover IRAs that we have via Schwab allowed us to buy 4- week T-Bills which is what we are doing there other than some other small amounts I play with on a couple of stocks.
After-Tax accounts (savings, etc.). We set up an account via
www.treasurydirect.gov that allows you to purchase Treasuries (T-bills again) directly - these are held in your name personally) in connection with an existing bank account you designate. When you buy, it drafts your account, when they mature, it automatically deposits them back to your banking account.
Would not be keeping much liquidity in traditional bank models at this time. Check your money market accounts with your bank. Some are FDIC insured and others are not. Even so, I don't have any desire to stand in line to file my claim and be prepared to wait years to get any recapture.
Others advocate keeping at least some cash on hand. Whether we get some interruption in traditional finance models (credit cards, etc..) or not, since you won't be sacrificing too much in lost yield, why not have a bit around.
This may or may not make sense for you or your personal situation, but if it offers you some insight, great.
Again, you may find a certified finanicial person that may well provide you with alternatives that would far outpace these suggestions, but I would steer clear of the general 'dollar cost average over time and believe the market will bring you happiness' approach as I think those that employ only that plan will find losses tough to swallow.
Hope this is of some value to you.