This was on slashdot a couple days ago http://punchscan.org/
The tradeoff is a simpler user interface (make one mark, instead of 1 or 2 per choice) but the election officials guard secrecy by having a giant one-time-pad secret key to decrypt everyone's ballots. I think I like Rivest's Three Ballot better. Brian Olson http://bolson.org/ ---- election-methods mailing list - see http://electorama.com/em for list info
