Just thought of another one...
When I was a kid I looked out of my bedroom window one Saturday afternoon and saw a light in the sky above the houses across the field. It looked like the white lights you occasionally see on the front of helicopters or aeroplanes, except that there didn't appear to be anything behind it.

It just hovered above the houses for a few seconds, then shot up into the sky really quickly (but not in a straight line) and then disappeared.

My mum was in the room at the time and she saw it too... after a couple of seconds silence she said "Well what was that then?". We're both quite into planes and aviation; it moved far too quickly to be a helicopter or aeroplane, and the sky was clear so it didn't disappear into some clouds or anything like that.
(Professor Kenny Martin Hmm? What?, Tue 8 Jul 2008, 14:36, Reply)