I think this is a good place to start. You could also start a Toronto Changemaker Group on the Changeblogger Network and direct people you meet who might be interested to join that group. You also might want to join the NetSquared Toronto Net Tuesday Meetup. They talk more generally about how nonprofits can use the social web, but there may be some bloggers, podcasters and vloggers who would like to join your Changeblogger group as well.