As much as I like iCloud, I still need to use a file storage service such as Dropbox because iCloud's offering is so limited in this area. It will only store and sync files created with Apple's iWork suite. I'm a big fan of Dropbox, and it's likely the most popular file-based cloud service. This is no doubt because it's utterly simple to set up and use. But it has some serious competition in Microsoft's SkyDrive and the new Google Drive.