Follow up to Mind Time
The Live Science article discusses research being done at Baylor University on why people have the sensation that time 'slows down' during stressful situations. Those researchers believe that this neurological phenomenon is related to how memories are formed rather than a physiological reaction like increased adrenaline. Basically, they argue that our brains tend to imprint memories in a deeper way when we're under stress than in normal situations; this leads to the sensation that time 'stretches' under stressful situations.
Interesting research. I don't know if it fully explains the 'mind time' phenomenon, but it sounds like a reasonable explanation. By the way, there is also a short video of the experiment.