I find that there are two different ways time gets stretched. The first is much like Heller described, being with annoying people, or being bored to tears. The other is when you are so wrappe dup in something new that you don't notice time passing. Then, after you are done, it feels like you were working twice as long.
I had a lot of that same feeling when I started working here. I think it's because your brain is getting all new experiences, and there is nothing that it can conveniently mark "seen it" and ignore. So it has to process everything, which I think makes it seem like there is "more time" between any two points.
Yeah. I was thinking about linking to http://ess.ntu.ac.uk/miller/cognitive/time.htm - an interesting point that what makes time drag in the short run might make it zip in the long, and vice-versa...