I've had this idea, I'm not sure if it has been done before:

You know that feeling you get where it seems like you have done/said/seen/heard a specific action or event at a specific location with a specific personnel as it happens? This phenomenon is what we call "Deja Vu." Now, what if everyone has this ability to briefly enter a parallel universe unknowingly, thus causing the phenomenon that is Deja Vu.

I think this idea could end up as a really cool backdrop for an rp. If anyone is interested, please help me come up with some ideas on to how we could make the rp work. Ideas for a plot line and characters would be appreciated as well. As of now, I'm pretty stumped. I think if we brainstorm a little, we could make something really cool.