A huge tip o' the hat to the folks at CBC.ca who have put their regional webcams all on one page. Where else can you see all of Canada at once?
And let's not forget the brilliant Katkam. Spetacular images of Vancouver's English Bay as well as links to other Lower Mainland webcams (scroll down). There's also a nifty archive that lets you see the last 14 days at one particular time.
It's so nice to be able to see the rain. ;)