Wow. A thread tailor-made for me, the budding astrophysicist.
Nezgruhel, the stuff you're talking about is mostly relativity, not quantum. The bit about time going faster or slower depending on relative velocities is known as special relativity, and time's dependence on gravitational fields is general relativity. I've had classes in both, but similar to what you said, my understanding of these things is far less than I'd like.
Most physicists feel that time is an intrinsic property of the universe, and only the units we measure in are arbitrary. Think about it like this: You're in a room with a table, but you don't have a meterstick. Does the table not have a length just because you can't measure it? The length (width, height, etc.) of the table is a property of the table, and it doesn't matter if someone is there to measure it or not. That's how most physicists view time... at least for now.
aka Reu, I like the philosophy, but I don't agree with the conclusion. We take "time" and mark it into seconds, minutes, hours, days, whatever... But even without us to do such things, the fundamental laws of physics would remain unchanged. The only "control" we have is in our ability to force (or recognize) different ways of measurement.
As a chocoholic, I whole-heartedly concur Xuri.
As for the non-ending cycle of Big Bangs, and the idea that our universe will eventually collapse back in on itself, the recent WMAP (Wilkinson Microwave Anisotropy Probe, I think) measurements indicate that not only is the universe still expanding, it's accelerating as well. As near as we can tell, this means that the "end state" of the universe is a slow heat death as the volume of the universe expands to infinity, not a violent re-collapse.
I like the idea of a quantum programming error, but that would only happen if I programmed it...
Syd, you're right, there was no time before the Big Bang. It's the "uncaused cause", or whatever, for any non-religious, scientific-minded person (which I don't claim to be). It's not something that's easily understood in any case.
Anyway, the "best" explanation I've heard of "time" is that time occurs because entropy is increasing. Every action, every event, every everything, increases entropy. Most people (even a lot of physicists) think of entropy as decay or disorder, but that's not quite it. Entropy is simply a measure of available states. For instance, a coin toss has a very low entropy, because the result is one of two states: heads or tails. A more complex system, say, three boxes with three different colored beanbags, has more entropy, because there are more available states. However, in the scenario of the heat death of the universe, there are too many available states for anything ordered to occur, statistically speaking.
Now that I've thrown out all that jumble of information, I'll vanish into the corner and watch the chaos that ensues.