Time travel back to 1000 A.D.: Survival tips

There is a fairly fascinating thread going on over at Marginal Revolution regarding unexpected time travel. The basic premise is this: suppose that you were suddenly transported back to 1000AD. You only have what you were wearing and your knowledge. What steps would you take to ensure your survival?

The entire thread is a _long_ read at the moment (and getting longer), but the suggestions range from the practical to the hilarious.

I don't know what I'd do; I can't even think past the inevitable massive caffeine-withdrawal headache.