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.
SkyDrive
