When it comes to the most personal files, it can be hard to trust the cloud. The iTwin USB dongle provides secure access to a computer's hard drive from any machine with a Web connection. Users plug half of the iTwin into a primary computer and set a password. Connecting the other half to another machine opens a direct link between the two. As files move between the pair, they are encrypted in 256-bit AES, the same standard used for military documents. If either half goes missing, both can be remotely deactivated. US$100