someone should make an Equel to Cameron's Titanic. Not a sequel or a prequel, but another film that happens at the same time, and could theoretically be watched side by side with it.
I love the concept of an Equel - a side-story of what else is happening during the story you're aware of. There are a few examples of this already - to varying degrees, Rosencrantz and Guildenstern are Dead, Catwoman: Her Sister's Keeper and the Buffy episode The Zeppo would fit this description (although there's a lot more to Rosencrantz and Guildenstern are Dead than that, and we've never seen the episode of Buffy that The Zeppo happens alongside).
Which films (or TV episodes, or whatever) would you like to see Equels to?
I'd like to see an action comedy taking place at the same time as The Terminator, dealing with the next Sarah Connor in the phone book - like After Hours but with more explosions. I just have this idea of halfway through her night of chaos she goes to the police station - just as it blows up.