Beware those red-and-blue maps behind Dan Rather's and Peter Jennings's heads.
The worst part about potential vote fraud, aside from the impossibility of fixing the problem after the fact, is that even fixable fraud may go unfixed.
On Election Night, the networks are going to do their best to satisfy the presumed demand for video-game-like speed and precision in results. They may not call Florida for Kerry before half the polls close, but they will put numbers up on those tote-boards.
Except that absentee, provisional, and in Colorado's case (see below) emergency ballots, will make up a large fraction of the vote. The networks will report results as authoritative that are either open to challenge, or only fractional. That initial reporting will cement a certain status as the "right one", giving the decision-making process a default position in the public's mind.
Those impressions can be very hard to overcome, and may add pressure to elections officials to certify results they have grave doubts about.
You know something? Forget all the frills. I use early voting, but I'd gladly give it up and stand in a school cafeteria for an hour if they also got rid of all but hardship absentee voting, register-by-palm-pilot, provisional voting, and same-day fifteenth chances to get it right. Go back to a system that reinforced civic ritual, minimized the chances for monkeying with the votes, minimized hand-counting, and kept Election Day from turning into Election Month.
This system is going to collapse under its own weight, trying to do too many things for too many people. Until they come up with retina-scan electronic voting machines that automatically configure themselves to your home precinct even though it's in another state, let's keep things simple.