Big Bang...How Did it Happen?

In my own small way, I'd like to offer a couple of analogies on the topic of expanding space and time.
First is a balloon: The expansion of space may be likened to the increase in surface area of the balloon when blown up. Where does the extra area of the balloon come from? Our understanding of 3space says that the additional area is a result of the stretching of the (fabric of the) balloon into the third dimension. This is an imperfect analogy as we AFAIK cannot observe expansion of space into another dimension.
Second is the Earth: Where is the beginning of a line of longitude? One can clearly travel along it for an infinite distance around and around the earth. So the accepted view of time as sequential and having a beginning may be a result of our limited scope of observation. Or you could consider the beginning of time to be now as the beginning of a journey may be said to be here.