I watched a program on Discovery Channel during "Human body week" about exactly this, time perception - though in stress situations. The program revolved around a firefighting-squad being trapped in a forest during a summer forest fire. The wind was picking up as they tried to outrun the fire. In a split second they had to decide what to do because the fire was very close, they told the interviewer that the time almost stood still when they stopped to make a life-saving decition. This was explained by the amount of adrenalin coursing through their system, affecting a part of the brain which makes decition-making a lot faster in stress situations. Don't ask me about the specifics, this was just what I saw - and I know you shouldn't believe everything you watch on TV, but this actually made sense.
Adrenalin is admittedly not only released in higher dosis in stress situations, but also when you get excited - this could be why lucid dreamers may experiance longer dreams because it shortens the process in making decitions and hence increasing time to do everything else.
This is not something that I know for sure, but I think that it makes sense. And I know that the previously posted article is contradicting this, but it has been 3 years since it was published and I suppose more research have been done.
