Making electronic voting, which should be completely transparent like any voting process IMO, open source just seems so obvious and I'm amazed that I don't see it mentioned at all in most of the articles on this topic (e-voting in the U.S.).

If it's open source and votes are digitally signed, then I think there's also 1) less of a need for a paper receipt, and 2) an easier way to do receipts if we must have them (just digitally sign the receipt the voter gets so it matches the one stored to disk).

Floppies are indeed a very fragile method of storing data; I cringe whenever I hear someone say the only copy of [important document] is on a floppy. In the Australian system linked above it sounds like they wrote votes to two disks per machine, but now that wireless networking is so pervasive and relatively cheap it might be better to just store it on a server over a wireless network for later upload.