Are objects in orbit around Earth considered part of the total mass of Earth?

I doubt that they are included always, it probably depends on what you're trying to calculate. If you have a number for it in some table, all objects in orbit around Earth are most likely not included.

Except for the moon, everything else originated from the earth anyway.

Didn't we once have a discussion about how much energy would be needed to change the orbit of earth to put it close enough to the sun that nobody would survive?

[quote author=iago link=board=36;threadid=5446;start=0#msg45982 date=1077732424]
Except for the moon, everything else originated from the earth anyway.
[/quote]
Not everything in the orbit originated from earth, I'm sure there have been some magical space rocks pulled into orbit.

[quote author=iago link=board=36;threadid=5446;start=0#msg45982 date=1077732424]
Didn't we once have a discussion about how much energy would be needed to change the orbit of earth to put it close enough to the sun that nobody would survive?
[/quote]
Probably

I would say it definitly is not included.

Here's an analogy similar to this statement:

Say you had a wallet (In this case the Moon), and there was a mugger standing on the same sidewalk (In this case universe). Now using force, the mugger could steal the wallet. Now that mugger would need a lot of force to do something like that though. And just like that, the wallet is no longer included! However, there's an exception to this as well, because using enough force maybe you could take a chunk off the Earth.

In this sense, the Moon is not part of the Earth because only gravity keeps it together. Maybe in the analogy the 'gravity' would be the person buying the wallet because they liked it.

Your analogy makes no sense.

The reason the mass of the earth would be important would be if you wanted to calculate, say, the momentum of earth. If you did, then you would include the moon, since it adds to the earth's inertial mass.

In general, though, when they say that the Earth is (?) 6 sextillion tons, I don't know if that would include the moon or not.

A more appropriate analogy might be a yo-yo. When you are holding the end of the string, does the mass of the wood part count? It's attached in a similar way to the moon, it seems.