In Canada you can file your taxes (and even get the replies via e-mail), renew your driver's licence, file for immigration changes (visa extensions, etc.), renew car plates, get a new passport, etc. all online. And yet, we don't feel we are secure enough to allow people to vote? How the fuck does that make any sense?
In the end, all this bullshit about "we can't provide enough security for voting" is just a smoke and mirrors job. The real fear is that everyone who doesn't vote now because it's a pain in the ass will start voting, and that could seriously change the political landscape.
And while you may be tempted to start giving me examples of how it's not a pain in the ass, such as how you can pre-vote with an envelope (wait, why is this allowed but online isn't?), or go physically in the morning/afternoon/whatever, NOTHING beats the ease-of-use of and time saving of online voting.