I LOVE the Fifth Element. I wish the DVD had more on it.

Yes, it's an homage. Horror films and sci fi do it all the time. Actually, most films do it. I had a teacher once (the same guy I was a teaching assistant for in the horror film class) who made us watch John Carpenter's They Live, and then spent the rest of the quarter talking about Lacan (quite lucidly) and showing us all the films Carpenter alludes to in They Live. These included Battleship Potemkin and Red River (I wish I could remember the others.). It was, despite the fact that They Live is a bad movie, a pretty great class.

Blade Runner astounds me, because it doesn't look dated. I mean, if you watch the Star Wars films, the effects look fairly hokey now. But Blade Runner is such a dank and dirty look at our future/present that it still holds up, even after two-and-a-half decades.