It turns out that Mint.com actually uses [Yodlee][1] for the back end, which does support Canadian banks. However, I've found their UI to be only OK at best. The actual website is called [Yodlee MoneyCenter][2].

I've recently discovered that [Thrive][3] supports all the Canadian financial institutions; you can enter any zip code to create your account.

It would still be nice if Mint started supporting Canadians...

  [1]: http://www.yodlee.com/
  [2]: http://www.yodlee.com/ymc_home.shtml
  [3]: http://justthrive.com