I used Dropbox to sync my files. But no laptop I know does what you asked. There are many reasons why. Why not Dropbox or a network share and sync?
Bob
Does it exist a laptop/tablet that becomes hard drive when connected to a desktop machine via USB?
I was looking for something with the following capabilities
1. you modify some files on the internal hard drive C: of the
laptop/tablet.
2. you switch off the laptop and connect it to a
desktop via USB cable
3. from the desktop you automatically see the C: drive
of the laptop and you can modify its files, just like a normal external hard
drive.
4. unplug the laptop, power it on and you can see the files
that have been modified by the desktop.
I have a similar machine called [Pomera by Kim Jim][1] , that is able to perform all the previous 4 steps but ONLY for text files.
I found it very convenient because, for example, you can copy on it a cpp file you were working on, you can modified it on the train, add some ideas, then when you arrive home, you plug the Pomera to the desktop and you can continue to work on the same file, since the gadget, once powered off behaves like a simple hard drive. But it can process only text files and you can't install any external software on it.

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