... with Dropbox.
Also, when on matter, you can backup your complete SC2 bank files. For that you need to place Dropbox directory on same drive as the where the SC2 bank files are created, then just make a junction:
Code:
c:\Users\user1\Dropbox\SaveGameBackup>mklink /J StarCraft2Banks "c:\Users\user1\Documents\StarCr
aft II\Accounts"
Junction created for StarCraft2Banks <<===>> c:\Users\user1\Documents\StarCraft II\Accounts
c:\Users\user1\Dropbox\SaveGameBackup>