Here's a much better link: (ASF format, 313MB, 640x480px)
(Link taken from here)
why does Americans see the need to constantly surround themselves with US flags? [...] Outside the USA, you'll only see it in dictatorships that tries to whip up unity/loyalty for to state
I think that's wrong. In Paris there flag poles on the street that serve no other purpose than to wave the French flag around. In Germany, following the last Euro cup, many people kept the German flags they had been displaying during the competition on their houses and cars (following a very long history of flag-taboo in that country, granted). In some neighbourhoods of my hometown of Montreal, hundreds of people display the Quebec flag on their porch for no other reason that affirm their patriotism.
I think we all have a natural tendency to notice flags much more when they have a negative connotation to us. Nationalist Quebecers notice Canadian flags everywhere but Quebec flags are invisible to them. Many people outside the US don't associate very positive thoughts to the Star-Spangled Banner, and the slight irritation it causes makes them notice it more.
And the picture we're discussing here is a military picture. Of course they're going to pose in front of their flag.
Just my $0.02 of course. Maybe the flag/capita ratio is indeed higher in the States than other countries, but I think that's the sort of domain where we're all heavily biased in what we notice and what we don't, so until I see actual figures I'll keep an eyebrow raised.