A pioneer in offering a massive 50 GB of free data storage for those using its service via mobile device or PC, Dropbox has had to deal with some embarrassing and disconcerting security issues in the past two years. In addition, questions were raised about the HIPAA or SOX compliance of an SMB offering it launched last year. However, it remains free and wildly popular for individual, nonbusiness-critical users and integrates with a growing number of apps on the iOS platform. It's available as a Web service, as well as on Android and iOS.
On a scale of 1-10: 7