Jonathan Rodden sends along this interactive webmap of 2008 precinct election results:
It is a pretty big improvement over the old county-level maps, and you can zoom in on metro areas and neighborhoods.
We have also made an atlas that makes it possible to superimpose the precinct election results on block-group-level race and income data. NYC (Brooklyn in particular) is fascinating.
How to report partial returns on election night
Seeing all these data reminds me of how I think they should report the partial vote totals on election night. Instead of saying, “With 14% of the precincts in, X percent of the vote is going to Mitt Romney,” they should say, “With 14% of the precincts in, the swing is Y percent toward the Republican ticket.” This would be much more informative, considering that those 14% are not a random sample of precincts. I don’t know why don’t they report the swing. I have the impression that they do it that way in Britain.