Even if you don't use multiple computers, you can use the Briefcase with a flash drive, if one's lying around. They're dead cheap nowadays.
In a nutshell, a Briefcase is a special folder that helps in keeping files and folders in sync with multiple destinations. You can use it in two ways:
Over the Network (multiple computers):
To use this feature, just start by creating a New Briefcase in a computer you travel with.
Keep it in the Documents folder, or anywhere you like. Name it as you wish. Now make sure that your computers are connected to the same network and can see each other. If not, then connect them and make the name of the workgroup of both computers the same, then reboot. Make sure file sharing is on on both PCs. To watch a guide to share files, folders, or entire hard drives over the network between Windows Vista/7 and Windows XP, go here.
Now, drag any file from your desktop, or lets call it the Primary Computer here. Put it into the Briefcase on the other computer, over the network.
Now, a copy of the file will go to the Briefcase on your Mobile Computer. You can access it on the go. When you are connected with the Primary Computer over a network again, you can open the Briefcase and click the button Update All Items. The files will be in sync again.
Using a Flash Drive (one computer, portable drive):
You can also use a USB key, an external hard drive or any such drive that you can take with you and run on any computer somewhere else. For that, simply create a Briefcase on the portable drive and sync the files and folders just like you did with the multiple computers.
