The first time I experienced this was on a flight from New York to Puerto Rico. I was puzzled and upon returning to my home, I had a talk with a couple of friends about this and they said it was very common in Europe when on planes bound for holiday destinations (as opposed to those just flying through the European capitals) 

Have been on many international flights in Asia and have never seen this, on the few domestic flights in China I have been on, I have not seen it. I did have a flight at some point with a colleague who was terrified of flying and although he did not applaud after landing he did express happiness.

People should shut up and leave the plane calmly without any pushing

I've experienced this on a flight from Toronto to Cancun Mexico, from Toronto to Shanghai and Shanghai to Toronto nothing.

They clap on any of the Russian airlines at all the time upon landing (culture I guess) perhaps for no other reason that the plane landed safely.  Indeed, it does happen.

Puerto Ricans have done this too....

first time experienced was landing @ Sheremetyevo International flying Aeroflot. Once again flying into Leningrad (yes, it was Leningrad then) and once again w/ Cubana upon landing in Habana.

to me the passengers were just expressing joy/amazement at still being alive.  haha 

actually this also happens back home, people always applause whenever a plane lands successfully, this is to show that the journey was a successful one and nothing happened to them.

I never experienced the same whenever i landed on Chinese Airport..

From my limited experience travelling by flight, not once. But I think people applause on Italian flights I get the idea from this video.

http://v.youku.com/v_show/id_XMTA4NTg0NDg4.html

Have fun watching it

I flew on an airline here where I saw some guy duct taping something on the wing shortly before take off.  I clapped when it landed.

In my previous career I used to see passengers onto aircraft, sort of a ground host, the baggage handlers had a 'trick', they'd come to the bottom of the steps to collect child buggies etc, and would be carrying a half roll of duct tape and a bag of assorted nuts and bolts, hand them to one of the other baggage handlers and say something like, I found these under the wing, just loud enough for the passengers to hear. Of course the passengers didn't know if they were technicians or baggage handlers and some of the looks on the faces were, well, funny to us. 

N.B. This was back in the 80s I don't think they'd get away with it now.

Long ago when I traveled to Puerto Rico I head some sporadic applause on the aircraft and was incredibly surprised. Mainly because the pilots will never see those claps from behind their door. Who those people applaude too only God knows. But was surprised that someone heard this in Europe. This sounds weird, never heard it anywhere in Europe.