If you've not yet discovered the wonderful podcast Hello Internet, then please let me recommend that to you. I love it. I have (well, had) no idea who CPG Grey or Brady Haran are, but their opposing characters are a source of such insight into the human condition that makes every episode enjoyable. Just two guys talking; well worth a listen. Recently they've brought up the notion of 'the void' - those times when people on a ship late at night feel drawn to jump into it for no good reason. A more everyday scenario they came up with was the posting of a letter. More specifically that moment just as your fingers are about to let go of the envelope into the post box. As it dangles there on the threshold there is that small voice saying 'do it, drop it in' which is countered by a nagging doubt that you've incorrectly addressed the envelope.
My void-esc moment comes when I turn the TV off (technically my Toppy PVR). There is a moment after you hit the button in which the TV remains on for a small period of time as if nothing has happened before the inevitable does happen. It strikes an odd chord with me, as if I feel some sadness that the TV is about to die, its fate is set, but not yet realized.
If I wanted to ponder deeper I'd bring up the documentary "Choosing to Die" that Terry Pratchett made a couple of years ago about Dignitas and assisted dying. That film really struck some part of me, not because I want to die (quite literally the opposite), but for that moment portrayed after the chap took the poison in which the inevitable is inevitable but before that inevitable had happened. Further back there was a Tomorrow World I remember which covered an Australian computer-assisted suicide (recently appears on QI). I can't think of the word to describe it, but both these states have the same flavour - that lingering moment of continuum before the change. Perhaps even the changeing of the seasons can exhibit the same temporal conditions. It's not quite 'the void' as such, but seems to me somehow related.
my old wide-screen CRT with exciting dust attraction quality