Website: dropbox.com
License: freeware
Difficulty: Easy
Dropbox offers 2GB (or more) of free online storage, but it is the free desktop application that makes this service so useful. When you install the application, it allows you to pick a location for the Dropbox folder. Any files or folder you put in this folder are synchronized to the online storage (up to your space limit). You can access these files from anywhere through dropbox.com, or using the app on Linux, Mac, and PC, an Android device, or an Apple device. Installing Dropbox on multiple computers makes it easy to share files from work to home, or desktop to laptop. You can also share files with regular web links.