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

I have a low taste for alternate history novels. This tickled my interest: Marginal Revolution: Time travel back to 1000 A.D.: Survival tips.

I hope you have an expensive gold wedding band but otherwise start off by keeping your mouth shut. Find someone who will take care of you for a few days or weeks and then look for employment in the local church. Your marginal product is quite low, even once you have learned the local language. You might think that knowing economics, or perhaps quantum mechanics, will do you some good but in reality people won't even think your jokes are funny. Even if you can prove Euler's Theorem from memory no one will understand your notation. I hope you have a strong back and an up to date smallpox vaccination.

Readers, do you have any other tips? Is there any way that Londenio can leverage his knowledge of modernity (he is, by the way, a marketing professor) into socially valuable outputs? Would prattling on about sanitation and communicable diseases do him any good?

I think the comments are particularly good.