My first few lines of code that actually created something. This loads cards.png and shows it on the screen. Might leak memory, not entirely sure (Update: yes, it leaked because addSubView incremented retain count).
UIImage *img = [UIImage imageNamed:@"cards.png"]; // who should release this?
self.sub = [[UIImageView alloc] initWithImage:img];
[sub release]; // to get retain count to 1