Can a resident math nerd calculate for us an approximate length of time a "dropped something" (a coin, perhaps) would fall from the top of this building before hitting the ground AFTER reaching terminal velocity?

http://en.wikipedia.org/wiki/Terminal_velocity

There is NO WAY you would EVER get me doing that ( shudders )...hell if that was me I'd have shit meself by now !

Well, I would have to puke all the time, but at least I could clean the mess instantly

I'm passing there everyday going to work.. Guys, I suggest you come visit Dubai, the city is so amazing..
You'll see this twisted building too: http://www.constructionweekonline.com/pictures/CG%20Pix/Infinity_1.gif

828 Meters high = 13 seconds for an object to hit the ground
http://www.gravitycalc.com/

Coins are flat, so they experience a lot of air resistance, and they are light, so it doesn't take much drag to counteract their weight. Thus, if hurled off a skyscraper, coins achieve their terminal velocity after only about 50 feet (15 meters) of descent. After that point, they flutter to the ground at a measly 25 mph (40 kph), Bloomfield said.

If there were no air, a falling coin would accelerate to a speed of 208 mph (335 kph) by the time it reached the ground (or your head). At that speed, it might very well damage your skull, but it wouldn't drill through.

I wonder if we can build that high once, the top wil in snow all year long.

What if these buildings had like a rail running down on each edge, with some arm extending out somewhat that runs top to bottom, spraying a huge amount of hot water from a pipe with an incredibly high pressure so that it reaches the middle of a side (between two edges).

The hot air falling down would just evaporate and not reach ground. Is it a stupid idea? Like fire trucks have + high pressure cleaner systems + lifts combined. No need for paying men continuously.
Or if this isn't doable, surely there could be a technological solution in this day and age. Or if this "running down at the edge" idea would only work on non-complex geometrical shapes, still if it does 50% of the job, still efficient.

#6 in those areas workforce is very cheap. At least it's cheaper than an automated system.
And you know how it works in our modern (capitalist) world : I don't care how it must be done, but I'll do it the cheapest way !

Wikipedia ==> "A study conducted in 2004 found the median salary range of Indian migrants to be between Dh 1,001—1,500 (between US$ 270—408) per month (or US$ 3,240—4,896 per year), considerably below the national per capita income of US$ 55,200"

1:06 The choice of music is brilliant! It's from Hitchcock's movie "Vertigo".

#5 so you could make a call to warn them that shit is raining! XD

3:4 his point it not true. At least there is one machine that is capable of cleaning high rise building's windows.
http://www.ipceagle.com/products/highrise