The difference between President Barack Obama and Republican challenger Mitt Romney is vast, yet a small but crucial segment of the electorate remains undecided. The BBC's Justin Webb asks why some US voters just cannot make up their minds between the two.
I must have cut a very strange figure on Miami beach the other day. It was very hot, sparkling sunshine, glorious waves - but I was not dressed for the seaside.

I was making a film for BBC's Newsnight programme and wearing a formal shirt and what one rather unkind correspondent described as "BBC trousers" - chinos with lots of pockets.

I had a microphone receiver jammed into a belt. And I was running. Madly. Helter skelter up and down the beach, looking for my lost wallet.

After 10 minutes I was soaking and panting, and still without it. Thinking it was gone for good, I dried off, addressed the camera, and went back to our hotel.