In real tournaments, are actual flags used? I've never seen one before.
If a flag falls in the forest...

That choice of words means that both players' flags could fall before either notices and claims. What happens then?

Digital clocks that are in common usage today don't allow both flags to fall, but when analog clocks are used, both could fall.
@macer75: My digital chess clock has lights and flag icons. When one clock runs out of time, both clocks freeze.

I'm not sure about if both players run out of time. But fide has a reputation going back a long way (and no improvement now either) of being absolutely incompetent in soooo many areas. I wouldn't be surprised if there were many more cloudy, confusing rules.

Oh and little plastic pieces on clocks that were mostly red were called flags. They would fall when the minutes hand passed under them representing 0 time left.
That choice of words means that both players' flags could fall before either notices and claims. What happens then?
6.11 |
If both flags have fallen and it is impossible to establish which flag fell first then: |
|
a. |
the game shall continue if it happens in any period of the game except the last period |
|
b. |
the game is drawn if it happens in the period of a game, in which all remaining moves must be completed. |

Oh and little plastic pieces on clocks that were mostly red were called flags. They would fall when the minutes hand passed under them representing 0 time left.
Oh, now i see. Thanks for the explanation!
I was reading someone else's post about time controls/draws and followed a link to the FIDE rules (thanks). Then I saw this:
6.8
A flag is considered to have fallen when the arbiter observes the fact or when either player has made a valid claim to that effect.
What an interesting choice of language. So if an official arbiter and both of the two players refuse to acknowledge a flag as fallen, and the crowd is yelling "it's over"...the flag has not fallen by definition. Oops, I take that back...the arbiter does not actually have to acknowledge the flag has fallen, they just have to observe it and can remain silent and the flag has fallen despite no acknowledgement. But in the absence of an arbiter, if a one player or both observe the flag falling and one does not make a claim, the flag has just not fallen. It never happened.
What a bizarre and imprecise way to write this up :).