The iTwin is labeled as the "USB Drive Reinvented," but it isn't a USB drive. What looks like a USB stick separates into two pieces that form a link between two PCs — and gives you easy access to your files wherever you go, just like a cloud server would.
There are multitudes of methods to access files from your desktop PC to work on them remotely on your laptop of hotel business center machine. Dropbox, for instance, or any cloud-based back-up service such as SugarSync.
Two problems with these cloud-based remote access solutions. One, they cost money to store a substantial number of files, and once you work on your file remotely, you have to remember to transfer it and re-save it on your home or office PC once you get back, or you end up with multiple versions, all with the same file name. Yuch.
With iTwin, you plug the whole business into your primary PC. You drag whatever files you want to access remotely. It's OS agnostic and there's no size limitation because what's "copied" aren't the files themselves, but shortcuts to those files. As a result, you can even drag over the entire contents of your hard drive.
Now separate the two halves, and stick the second into your laptop's USB jack. Voila, you have access to all your files in their correct file folders. Edit to your heart's content and save, and those edits are reflected in the original files back home.
The remote half of iTwin is AES 256-bit encrypted to keep nosey bodies out of your business. If you lose the traveling half (its key weakness - the thing is kinda tiny), whoever finds would have to break the encryption to get at your stuff. And, in case of loss or theft, you can just order the second half ($50).