I usually experience Deja Vu when I'm in the flow state. I went very deep into the flow state today - it was a "calm paranoia," to say the least. My senses were peaking as if in a life-or-death panic, yet I was utterly relaxed (even the cross of my back where I cary most of my tension), and I new I was in no danger at all. I had a feeling that I was reliving something that happened very, very recently. Like I was a "fleeting moment" ahead of everything.
The real question on Deja Vu is what one can do to trigger awareness of what happens next, before it happens. Precognition, ya dig?