I have been unable to find an option pricing chain for real estate at the CME although I believe one exists if you are a CME member or have a broker who is. You should be able to buy 2011 puts in 5 point increments from today’s current Case Shiller price, and hedge that way. The put gives you the right to sell at today’s prices for whatever premium they charge.

BTW, Shiller has been so visible recently because he licenses his data and in addition to the futures and options market he is trying to work with insurers who would do the hedging for you and issue “equity insurance” of sorts.

I don’t know much about futures/options theory, but I can’t believe this is a very efficient market right now because it’s so thinly traded.

BTW there is an outfit called REX and Co. that offers a deal where they will give you free use of some of your current equity in exchange for a percentage of the gain/loss on your home when you sell. It’s not a loan. It seems like it might be a good hedge if you are selling in the next 2-4 years and have a lot of equity.