Aww, thank you everyone (and have a star, Caterpillar!) - I really appreciate it.
So, the gory details then...
I'd like to start off by saying that it really wasn't that bad. I had two experienced examiners and it didn't feel anything like the Spanish Inquisition. From my newly acquired experience the viva is not a deadly interrogation, it is not aggressive and you should not have any reason to feel afraid (maybe just a little nervous - but that settles). Best way to imagine it, is to picture yourself sitting in a cafe having an interesting intellectual debate on your subject of interest with two equally intelligent companions. Really, all the do is ask for clarification on certain areas of your work, challenge you regarding certain assertions you make with their beliefs. There is not necessarily a right or wrong answer. If you don't know something, or aren't certain, just admit it or state that you will deal with it in further research. Say, 'that's an interesting perspective that I haven't considered'. After all, you're not expected to be omniscient. And the books on viva examinations - pah. I'm glad I never bothered practising the questions in them - because I was asked none of them. You really can't predict what you will be asked - it's so subjective and thesis-specific.
I knew my thesis inside out and a little bit about the broader area of research around it - and that was more than enough. The areas that Bilbobaggins mentions to bear in mind, such as your contributions to knowledge and so forth, really, really are enough. Don't be masochistic and practice a 101 questions - know your thesis, the different sections, inside-out.
I'll put the viva format and general questions in the next post, just in case I run out of space in this post.