Sky Tree. It's a big TV tower. The tallest tower in the world and the second tallest structure, after the Burj Khalifa. And, if I'm reading Wikipedia right, it's also the tallest structure on an island? Couldn't they just stop at "tallest tower in the world"? Anyway, yesterday they announced the price to go to the observation decks: 2000 yen to go to the lower deck at 350 meters and 3000 yen to the upper deck at 450 meters. That's almost 40 bucks, with the yen as strong as it is. On Twitter yesterday, Nikkei Trendy set off a wave of price comparisons for tall buildings around Japan when they calculated a trip up Tokyo Tower at 5.68 yen/meter and Sky Tree at about 6.67. One reader pointed out that the Shin Umeda Sky Building in Osaka was a bargain at just 4 yen/meter, but my pal Durf won the day with some back-of-the-envelope math.