The speed of light is generally compared to a natural speed barrier. This is actually misleading. The nature of the universe (at least the part that we have observed until now) behaves in such a manner as to make speed of light undefined for objects with non-zero mass. That is to say, there is no such thing as "going at the speed of light". At the speed of light, concepts of time, space and mass lose their meaning.
Allow me to just write that sentence again: At the speed of light, concepts of time, space and mass lose their meaning. The photons which have no mass do not "observe" the passage of time. You could possibly comment that the photons feel the passage of space in the way we (we the non-zero mass particles) observe the passage of time. In a very literal sense, time does not just stop at the speed of light: It ceases to exist, in the sense that it loses its definition.
Therefore, we can say that the we all live in an orb with the diameter of the speed of light, and our observable universe has this limitation. To cross this limitation is not a matter of technology or advancement - crossing it would be as meaningless as digging a straight tunnel that is longer than two times the radius of Earth. Or as meaningless as dry water - it exists in grammar, but not in real life.
Another implication of the Theory of Relativity is that there is no such thing as simultaneous. A person on Earth and on Alpha Centaury (4.5 light years apart) cannot do something at the same time. Read that again - this sounds awkward. Surely, one would think that if two planes start from Alpha Centaury and Earth at the same time and travel to each other at half the speed of light, they will rendez-vous in the middle in 4.5 years. However, notice the italics: To be actually able to start at the same time, they would first need to establish a common reference frame. Although practically possible (has to be done 9 years prior at the very least) it still does not mean simultaneity occurs - something similar to our experience of simultaneity will occur only when the ships have actually met.
To explain in other words, there is no such question as "what is going on in Alpha Centaury right now?" The closest you can some to that question is: "What will have gone on in Alpha Centaury when its light reaches us 4.5 years from today according to our frame of reference?" This is because "right now" in Alpha Centaury, according to our frame of reference, will have occurred 4.5 years from now.
Is there any way that I might be wrong? Yes, but no. The relatively-new theory (relative to the theory of relativity - nice!) called the string theory requires some parts (and some information) to travel faster than light. However, those parts and communications occur at below the Planck distance, (10-21 = so small thinking about it makes my pathetic brains explode) and I believe that they have no effect on the our scale. (See my next blog post about time travel for why I think that way.)
It might be conceivable that a new explanation of all the phenomenon that the Theory of Relativity explains today. However, even if such an explanation is put forward, it would have to explain the problem of simultaneity in a way that does not conflict with our current experiments. In a very real sense, it would make "time" meaningless, or rather, no different than distance. Note that even the article linked above does attempt to circumvent the Theory of Relativity. If you do travel 2 million light years in space by warping space-time by changing the 11th dimension of the string theory, or by finding a "wormhole", you have also travelled at least 2 million years into the future. You are not coming back!
Therefore, the speed of light is not a physical barrier, it is a property of the universe that is closely related to the passage of time. To call it a barrier is misleading, and we fail to grasp the nature of the problem: Mingle with the speed of light, and you mingle with the fabric of the reality as we know it.
(And here is the story of an effect that may be happening before its cause: http://dsc.discovery.com/news/2006/05/24/weirdlight_spa.html )
(And here are cool science pics: http://orbitingfrog.com/blog/2007/07/25/the-10-strangest-real-things-in-space/comment-page-1/)