One of the most important skills an author can develop is the ability to describe their book concisely. To trim off all the fat and get to the heart is an amazing skill that let's the people you meet know that you understand your own book instead of rambling on about how this happens... and then this other thing, which is really cool because it makes the next thing really funny, but that none of that really makes sense unless you know this about the backstory.
You can leave people dizzy!
So read the following comments to see how authors are describing their books in 30 seconds for fiction and 60 seconds for non-fiction (non-fiction authors have to talk about themselves briefly and explain why they are qualified to write a book on their chosen subject, so they get double time).
And if you're publishing your book in the near future, be prepared to do the same :)