Briefcase
<tool> A Win95/{WinNT} utility for keeping files on two computers without permanent connection in sync.
The scenario briefcase was designed for is the combination of an office computer and a portable one.
You connect the two before leaving your office, create a briefcase on the portable (if you don't already have one on it), then copy the files you want to work on while away into the briefcase.
You can at this point disconnect the two computers, take the portable with you and work on the files in the briefcase at home or on the road.
When you get back to your office the briefcase utility can automatically update the files you changed on the office computer.