http://fightspam.gc.ca/eic/site/030.nsf/eng/home
It's kinda nice in a way, but also seems useless too. This only applies to Canadian entities, but a lot of spam comes from outside of Canada where this law can't really touch them.
I've been getting a lot of emails lately from the bigger companies though, asking if I consent to them sending spam to me. That's a start, I think.