yeah you keep whatever movie you want for as long as you want, but to get another movie you have to return one. you can do 3 at a time unlimited or whatever suits your needs. its month to month, so if you decide to cancel you have to return the movies in the mail or they charge you. I have no idea if its in canada. check out www.netflix.com and find out.
oh yeah, if you've got any of the unlimited at a time plans you get free movie streaming online. quality is decent for streaming, not as good as hulu, but pretty good for un-interupted movies and tv shows. I hook up my laptop to my TV via an HDMI connection and stream movies in surround sound all the time, its awesome.