Last summer when we were in Vancouver we took a couple of free walking tours given by the Architectural Institute of B.C. They offer six in total (we did the Chinatown and West End ones). They also give five in Victoria. We really enjoyed them and learn a lot about the city we grew up in. You can get them to send you electronic or snailmail brochures by emailing tours@aibc.bc.ca or check out their web site at tours