At first, the iTwin seems to solve a problem that's already been taken care of--sharing and syncing documents remotely. But while services such as Dropbox are useful, you're limited to just 2GB before you have to start paying a monthly fee. For $99--with no additional fees or subscriptions--iTwin lets you create a secure link over the Internet between your home and work PCs, creating a single, unified storage structure that's only limited by the size of your computer's hard drive. But is it as effective as it is simple? Read on to find out.