Planning a trip to Montreal

I am currently planning to attend Anticipation, the 67th World Science Fiction Convention (aka Worldcon 67), in Montreal this August. While I do plan on spending most of my time at the convention, I'm staying an extra day to do some sightseeing. Is there anyone out there who can offer suggestions on attractions in the area?

I've already read every review Epinions has on Montreal, but not a whole lot there piqued my interest, except the descriptions of Old Montreal.

As usual, my interests are history and haunted locations. The Old Montreal Ghost Hunt (a walking tour) is already on my list of things to do.

Any help will be appreciated.