Sock, you said previously:

...and judging by the posts in this thread, I fear many of you would be toast.

So, in summary, it seems that the useful skills/strategies metioned thus far are:

1) Hide and live off the land. (standard survival skills)
2) Some sort of shiphand, navigator.
3) Get in with the clergy. (good understanding of latin / theology)
4) Travelling entertainer / minstrel (Only good if you are Blast.)
5) Try to impersonate a noble.
6) Write messages in a cave, hoping that someone in the future with a time machine can save you.

Have I missed anything?

I'd add one other to Mike_H's list, which was not mentioned and I just thought of, but might very have you changing the course of history: advise someone on how to make war, if you have any concept about creating weapons or, possibly, tactics.

If you are the guy who knows how to make gunpowder or any explosive, then you risk being burned as a witch or something. But the upside may be that the King hires you to create a whole bunch for him.

I think you'd need to get past the first few months to be able to use this.

Wait 66 years and place a bet on the battle of hastings winner. Or if you can remember the right sulphur/charcoal/saltpeter mix for gunpowder; fix the fight!
The Sock

"...Wait 66 years..."

Might be a hard thing to do, considering how young people died back in those days...

Attending the battle of hastings wouldn't be a safe bet either. Just being near an army was dangerous. They didn't have the safet culture we have.
I noticed in the bayeux tapestry one of the norman archers is pointing his strung bow around all around.
He'll have someones eye out with that thing.
The Sock