dropbox is fine if I'm sharing with one or two people and all the files are necessary to me (and there aren't a billion of them). If there are 1000 files and I'm only concerned with 10 of them, the fuck if I want all that shit on my HD!
If I want a local copy of something from GDocs I just go to File>Download As... and I save a fuggin copy to my HD.
It's kind of like how when I send CEO all my noodz, we wouldn't them all saved to his computer. Thatd be inconvenient.