Just saw a nifty show on the science channel called
time limits about the limits of our perception of time.
One of the important points that it mentions that I think is worth more than casual consideration is that our perception of time (or rather the universe as time passes) is not continuous, even though it seems continuous to us. We sample the universe through our senses; we take a little dip of the available information the universe is presenting us with, break it apart, analyze it, prioritize elements, mark some things for attention, tuck a couple others as potentially important and then take a new sample and start all over again.
But we never usually realize that we aren't taking a steady stream, our experience of consciousness is of a smooth fairly steady flow. At most we become aware that in some, often highly emotional, circumstances things seem to slow down and we might be taking a larger stream other times things seem to pass in an instant but always a steady hum of conscious perception.
But that's just not the way we work. anything that happens in under ~1/16th of a second is usually too fast for us to notice. Take movies and television, a succession of still images we put together into something that seems to us to move.
Dennet takes that idea further and believe that consciousness doesn't really exist, it is an amalgamation of our memories to produce the illusion of conscouness.