What prompted this from DH was that when we were discussing South Dakota, is that the entire state of SD has roughly the same population as the city of Columbus--but they get 3 electoral votes. I'm sure he could support his position with pie charts and graphs and stuff.
Actually, every mathematical analysis I've seen has shown that the electoral college gives more power to voters in larger states. Basically, it's true that a citizen of South Dakota has a bigger influence on where South Dakota's votes go than a citizen of Ohio has on where Ohio's votes go, but Ohio's votes have a bigger influence on where the country goes -- it's a pretty rare election that will be decided by South Dakota's three votes, whereas it's much more likely that Ohio going one way or the other will make a difference. Once you compute all the probabilities together, it ends up that the people in the bigger states have more power.
Personally, I don't totally like this analysis, because all the probabilities are built on the assumption that there's an equal chance of any outcome -- pretty much, when calculating how much power a citizen of Ohio has to influence the election, it goes with the assumption that there's an equal chance that California will go Democrat or Republican. I've played around with the numbers a little bit -- nothing formal, just some "hey, what if...?" things -- and pretty well convinced myself that the electoral college gives the most power to people in large swing states. (Which seems to be borne out pretty well by the real world -- Florida and Ohio would both count as large swing states.)