Most of the replies seem to follow this same basic logic:
1) Arrive in past. Know you are awesome and handsome because of your better diet.
2) Use your awesomeness to meet king. If threatened, breakdance.
3) Impress king with awesomeness/breakdancing skills. Become Chancellor.
4) Perhaps build something awesome, you know, with gears and shit.
5) Seduce queen (see: breakdance), sire many half-royal, half-awesome progeny.
6) Upon death of king, rule country as regent through children.
7) Inscribe a message to your future self on clay/stone/metal tablets alerting yourself about your impending timetravel and the need for adequate breakdancing skills.
When what’s more likely is:
1) Arrive in past. Know that you are awesome and handsome because of your better diet.
2) Die horribly due to malnutrition, exhaustion, disease, animal attack, Viking attack, stake burning, eating the wrong mushroom, eating the right mushroom, parasites, or lack of internet access.
— “Robocop is bleeding” sums it up in Metafilter’s thread about medieval time travel.
