You can get 5L mini-kegs of Warsteiner at certain BC Liquor Stores. Unfortunately Canadian and Sleeman aren't available anymore.
They're no cheaper than bottles ($25 for 5L) but they sure look cool
Heineken kegs are $$$ for some stupid reason.
Damn, where do you get this mythical BeerTender? That thing looks CRAZY sweet. Now I want one ><