Install Assetbox on them all, then when you make a change to a file on one, it will be synchronised to them all - instantly. You'll see the same files everywhere you need them and never lose a change to a document again.
You can choose which folders to synchronise and files are never deleted from your computer permanently so if you make a mistake there's no need to worry.
What's more, with Assetbox installed your data is securely backed up as you work. Your files are safely stored in a vault within moments of you saving them so your data is always protected.
Available for Windows XP/Vista only. Mac & Linux version coming 2009.