Faster than light travel, and by extention time travel.
EDIT: Just had another thought on this, I'm not saying that we'll never be able to travel around the universe, because wormholes would work. I'm just commenting that faster than light speeds can not be reached by pure acceleration. Though a wormhole doesn't really speed you up, it just makes the distance between the two points zero. Which is entirely different to faster that light travel.
bigolbear said:
an artificial inteligence that can out think a human on anything OTHER than its very specific topic(eg chess) and can do so while perceiving and interacting with its environment as we do.
personaly i dont think that good ai will ever realy happen cos we wont build it, we may work out how - but we wont use it. Even the military who are the usual culprits for tech abuse wouldnt go near this because its much beter to have a soldier that folows ords WITHOUT thinking for itself.
This is actually true, you can't make something thats smarter than you. Why? Because you won't be smart enough to understand how to make it.