There's a relevant Mitchell and Web scetch. Someone travels back in time and meets Faraday. Faraday asks a bunch of questions, none of which can be answered because the traveller is just an everyday person who has little clue about how things work.
You may have been thinking of this sketch:
http://www.youtube.com/watch?v=oa_hiLXLbTc
Where one guy proposes a modern idea but it makes no sense to people of the past. I think this is one of a 2 or 3 such sketches.
There's a slightly silly-but-entertaining film in which an aircraft carrier goes back in time. The spoiler of the film is that one man who is left behind in time becomes absurdly rich by becoming a pioneering "inventor".
So we should look for absurdly rich people who have made dozens of inventions.
I believe that there was a similar premise in a series of Star Trek: Voyager episodes, where a businessman steals a time traveler's technology and uses it to bootstrap the modern computer industry.
