How can I access Dropbox in USB Disk?

To connect to Dropbox, press the "Edit" button on USB Disk's home screen. Then press the "Add" cell that appeared. Select "Dropbox" as the type of server you want to connect to, enter your user name, then press the "Link account" button. Follow the instructions on the screen to link your account: enter your Dropbox user name and password, then grant access for USB Disk. Finally, press "Done" twice. This will add a new item on the home screen. Pressing it will let you browse the files on your Dropbox as you browse local files.