Whew...I just read the last ten pages to get caught up!

Sucks not having the internet at home right now.
I love reading everyone's thoughts on this film, I've seen it twice now, and hope to experience it a third this week. I think the mysteries that surround the story are awesome...lets us think and come up with our own conclusions. There's really not THAT much left to the void though, semi-solid conclusions can be drawn based on what was given to us.
Some things I've wondered about, but I don't remember anyone suggesting on here, are:
Why did they want to destroy us? Maybe that was their goal all along. I think of the human race as being just one of many science experiments. And once the experiment has reached it's apex, it's time to clean slate and start over. By leaving behind some "clues" on Earth (and maybe other worlds) as to their origins and a form of "invitation"...once the native dominant species was evolved and intelligent enough to translate the maps and follow them...the Engineers would then know their experiment had reached it's goal. When the explorers would reach the planet, it would be a signal to the military Engineers that it's time to head back to that world to unleash the bio-weapons and then eventually start fresh with something new. That's my take...right or wrong.
I also wonder if each of the Engineer military ships had a different form of the alien "goo". David said the ship they found was destined for Earth (a stretch of a coincidence with the first ship they find, but who cares), but what if each of the other (dozens did he say?) ships were destined for separate worlds? Each one with a variation of the bio-weapon best suited for cleansing of that particular world? So what if then the ship carrying the eggs and traditional species variety as seen in Alien films was originally intended for another planet and race all together, yet is the one that humans ended up having contact with the most?

There are countless strains of virus and bacteria used (potentially) as bio-weapons in the real world, so what if there are various strains of the xenomorph? I'm probably way off track, but these are fun ideas I've been toying with.
I do like the idea some of you threw out there about how the "goo" was originally developed by studying the traditional xenomorph, and that the ship seen in Alien was more of a scientific cargo than military weapon.
One more thing. Can we assume that the ship Dr. Shaw and David flew away with to find the Engineers home world was also filled with bio-weapons? Can you imagine the kind of welcome they would get with THAT?
